diff --git a/src/appkit/app/class.rs b/src/appkit/app/class.rs
index e53885f..2b46ae7 100644
--- a/src/appkit/app/class.rs
+++ b/src/appkit/app/class.rs
@@ -12,12 +12,17 @@ use objc::runtime::Class;
 pub(crate) fn register_app_class() -> *const Class {
     static mut APP_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTApplication";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSApplication);
-        let decl = ClassDecl::new("RSTApplication", superclass).unwrap();
-        APP_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { APP_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSApplication);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            APP_CLASS = decl.register();
+        });
+    }
 
     unsafe { APP_CLASS }
 }
diff --git a/src/appkit/app/delegate.rs b/src/appkit/app/delegate.rs
index 45cf6d9..d5e2069 100644
--- a/src/appkit/app/delegate.rs
+++ b/src/appkit/app/delegate.rs
@@ -297,173 +297,178 @@ extern "C" fn delegate_handles_key<T: AppDelegate>(this: &Object, _: Sel, _: id,
 pub(crate) fn register_app_delegate_class<T: AppDelegate + AppDelegate>() -> *const Class {
     static mut DELEGATE_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTAppDelegate";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSObject);
-        let mut decl = ClassDecl::new("RSTAppDelegate", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { DELEGATE_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSObject);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        decl.add_ivar::<usize>(APP_PTR);
+            decl.add_ivar::<usize>(APP_PTR);
 
-        // Launching Applications
-        decl.add_method(
-            sel!(applicationWillFinishLaunching:),
-            will_finish_launching::<T> as extern "C" fn(&Object, _, _)
-        );
-        decl.add_method(
-            sel!(applicationDidFinishLaunching:),
-            did_finish_launching::<T> as extern "C" fn(&Object, _, _)
-        );
+            // Launching Applications
+            decl.add_method(
+                sel!(applicationWillFinishLaunching:),
+                will_finish_launching::<T> as extern "C" fn(&Object, _, _)
+            );
+            decl.add_method(
+                sel!(applicationDidFinishLaunching:),
+                did_finish_launching::<T> as extern "C" fn(&Object, _, _)
+            );
 
-        // Managing Active Status
-        decl.add_method(
-            sel!(applicationWillBecomeActive:),
-            will_become_active::<T> as extern "C" fn(&Object, _, _)
-        );
-        decl.add_method(
-            sel!(applicationDidBecomeActive:),
-            did_become_active::<T> as extern "C" fn(&Object, _, _)
-        );
-        decl.add_method(
-            sel!(applicationWillResignActive:),
-            will_resign_active::<T> as extern "C" fn(&Object, _, _)
-        );
-        decl.add_method(
-            sel!(applicationDidResignActive:),
-            did_resign_active::<T> as extern "C" fn(&Object, _, _)
-        );
+            // Managing Active Status
+            decl.add_method(
+                sel!(applicationWillBecomeActive:),
+                will_become_active::<T> as extern "C" fn(&Object, _, _)
+            );
+            decl.add_method(
+                sel!(applicationDidBecomeActive:),
+                did_become_active::<T> as extern "C" fn(&Object, _, _)
+            );
+            decl.add_method(
+                sel!(applicationWillResignActive:),
+                will_resign_active::<T> as extern "C" fn(&Object, _, _)
+            );
+            decl.add_method(
+                sel!(applicationDidResignActive:),
+                did_resign_active::<T> as extern "C" fn(&Object, _, _)
+            );
 
-        // Terminating Applications
-        decl.add_method(
-            sel!(applicationShouldTerminate:),
-            should_terminate::<T> as extern "C" fn(&Object, _, _) -> NSUInteger
-        );
-        decl.add_method(
-            sel!(applicationWillTerminate:),
-            will_terminate::<T> as extern "C" fn(&Object, _, _)
-        );
-        decl.add_method(
-            sel!(applicationShouldTerminateAfterLastWindowClosed:),
-            should_terminate_after_last_window_closed::<T> as extern "C" fn(&Object, _, _) -> BOOL
-        );
+            // Terminating Applications
+            decl.add_method(
+                sel!(applicationShouldTerminate:),
+                should_terminate::<T> as extern "C" fn(&Object, _, _) -> NSUInteger
+            );
+            decl.add_method(
+                sel!(applicationWillTerminate:),
+                will_terminate::<T> as extern "C" fn(&Object, _, _)
+            );
+            decl.add_method(
+                sel!(applicationShouldTerminateAfterLastWindowClosed:),
+                should_terminate_after_last_window_closed::<T> as extern "C" fn(&Object, _, _) -> BOOL
+            );
 
-        // Hiding Applications
-        decl.add_method(sel!(applicationWillHide:), will_hide::<T> as extern "C" fn(&Object, _, _));
-        decl.add_method(sel!(applicationDidHide:), did_hide::<T> as extern "C" fn(&Object, _, _));
-        decl.add_method(sel!(applicationWillUnhide:), will_unhide::<T> as extern "C" fn(&Object, _, _));
-        decl.add_method(sel!(applicationDidUnhide:), did_unhide::<T> as extern "C" fn(&Object, _, _));
+            // Hiding Applications
+            decl.add_method(sel!(applicationWillHide:), will_hide::<T> as extern "C" fn(&Object, _, _));
+            decl.add_method(sel!(applicationDidHide:), did_hide::<T> as extern "C" fn(&Object, _, _));
+            decl.add_method(sel!(applicationWillUnhide:), will_unhide::<T> as extern "C" fn(&Object, _, _));
+            decl.add_method(sel!(applicationDidUnhide:), did_unhide::<T> as extern "C" fn(&Object, _, _));
 
-        // Managing Windows
-        decl.add_method(sel!(applicationWillUpdate:), will_update::<T> as extern "C" fn(&Object, _, _));
-        decl.add_method(sel!(applicationDidUpdate:), did_update::<T> as extern "C" fn(&Object, _, _));
-        decl.add_method(
-            sel!(applicationShouldHandleReopen:hasVisibleWindows:),
-            should_handle_reopen::<T> as extern "C" fn(&Object, _, _, BOOL) -> BOOL
-        );
+            // Managing Windows
+            decl.add_method(sel!(applicationWillUpdate:), will_update::<T> as extern "C" fn(&Object, _, _));
+            decl.add_method(sel!(applicationDidUpdate:), did_update::<T> as extern "C" fn(&Object, _, _));
+            decl.add_method(
+                sel!(applicationShouldHandleReopen:hasVisibleWindows:),
+                should_handle_reopen::<T> as extern "C" fn(&Object, _, _, BOOL) -> BOOL
+            );
 
-        // Dock Menu
-        decl.add_method(
-            sel!(applicationDockMenu:),
-            dock_menu::<T> as extern "C" fn(&Object, _, _) -> id
-        );
+            // Dock Menu
+            decl.add_method(
+                sel!(applicationDockMenu:),
+                dock_menu::<T> as extern "C" fn(&Object, _, _) -> id
+            );
 
-        // Displaying Errors
-        decl.add_method(
-            sel!(application:willPresentError:),
-            will_present_error::<T> as extern "C" fn(&Object, _, _, id) -> id
-        );
+            // Displaying Errors
+            decl.add_method(
+                sel!(application:willPresentError:),
+                will_present_error::<T> as extern "C" fn(&Object, _, _, id) -> id
+            );
 
-        // Managing the Screen
-        decl.add_method(
-            sel!(applicationDidChangeScreenParameters:),
-            did_change_screen_parameters::<T> as extern "C" fn(&Object, _, _)
-        );
-        decl.add_method(
-            sel!(applicationDidChangeOcclusionState:),
-            did_change_occlusion_state::<T> as extern "C" fn(&Object, _, _)
-        );
+            // Managing the Screen
+            decl.add_method(
+                sel!(applicationDidChangeScreenParameters:),
+                did_change_screen_parameters::<T> as extern "C" fn(&Object, _, _)
+            );
+            decl.add_method(
+                sel!(applicationDidChangeOcclusionState:),
+                did_change_occlusion_state::<T> as extern "C" fn(&Object, _, _)
+            );
 
-        // User Activities
-        decl.add_method(
-            sel!(application:willContinueUserActivityWithType:),
-            will_continue_user_activity_with_type::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
-        );
-        decl.add_method(
-            sel!(application:continueUserActivity:restorationHandler:),
-            continue_user_activity::<T> as extern "C" fn(&Object, _, _, id, id) -> BOOL
-        );
-        decl.add_method(
-            sel!(application:didFailToContinueUserActivityWithType:error:),
-            failed_to_continue_user_activity::<T> as extern "C" fn(&Object, _, _, id, id)
-        );
-        decl.add_method(
-            sel!(application:didUpdateUserActivity:),
-            did_update_user_activity::<T> as extern "C" fn(&Object, _, _, id)
-        );
+            // User Activities
+            decl.add_method(
+                sel!(application:willContinueUserActivityWithType:),
+                will_continue_user_activity_with_type::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
+            );
+            decl.add_method(
+                sel!(application:continueUserActivity:restorationHandler:),
+                continue_user_activity::<T> as extern "C" fn(&Object, _, _, id, id) -> BOOL
+            );
+            decl.add_method(
+                sel!(application:didFailToContinueUserActivityWithType:error:),
+                failed_to_continue_user_activity::<T> as extern "C" fn(&Object, _, _, id, id)
+            );
+            decl.add_method(
+                sel!(application:didUpdateUserActivity:),
+                did_update_user_activity::<T> as extern "C" fn(&Object, _, _, id)
+            );
 
-        // Handling push notifications
-        decl.add_method(
-            sel!(application:didRegisterForRemoteNotificationsWithDeviceToken:),
-            registered_for_remote_notifications::<T> as extern "C" fn(&Object, _, _, id)
-        );
-        decl.add_method(
-            sel!(application:didFailToRegisterForRemoteNotificationsWithError:),
-            failed_to_register_for_remote_notifications::<T> as extern "C" fn(&Object, _, _, id)
-        );
-        decl.add_method(
-            sel!(application:didReceiveRemoteNotification:),
-            did_receive_remote_notification::<T> as extern "C" fn(&Object, _, _, id)
-        );
+            // Handling push notifications
+            decl.add_method(
+                sel!(application:didRegisterForRemoteNotificationsWithDeviceToken:),
+                registered_for_remote_notifications::<T> as extern "C" fn(&Object, _, _, id)
+            );
+            decl.add_method(
+                sel!(application:didFailToRegisterForRemoteNotificationsWithError:),
+                failed_to_register_for_remote_notifications::<T> as extern "C" fn(&Object, _, _, id)
+            );
+            decl.add_method(
+                sel!(application:didReceiveRemoteNotification:),
+                did_receive_remote_notification::<T> as extern "C" fn(&Object, _, _, id)
+            );
 
-        // CloudKit
-        #[cfg(feature = "cloudkit")]
-        decl.add_method(
-            sel!(application:userDidAcceptCloudKitShareWithMetadata:),
-            accepted_cloudkit_share::<T> as extern "C" fn(&Object, _, _, id)
-        );
+            // CloudKit
+            #[cfg(feature = "cloudkit")]
+            decl.add_method(
+                sel!(application:userDidAcceptCloudKitShareWithMetadata:),
+                accepted_cloudkit_share::<T> as extern "C" fn(&Object, _, _, id)
+            );
 
-        // Opening Files
-        decl.add_method(
-            sel!(application:openURLs:),
-            open_urls::<T> as extern "C" fn(&Object, _, _, id)
-        );
-        decl.add_method(
-            sel!(application:openFileWithoutUI:),
-            open_file_without_ui::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
-        );
-        decl.add_method(
-            sel!(applicationShouldOpenUntitledFile:),
-            should_open_untitled_file::<T> as extern "C" fn(&Object, _, _) -> BOOL
-        );
-        decl.add_method(
-            sel!(applicationOpenUntitledFile:),
-            open_untitled_file::<T> as extern "C" fn(&Object, _, _) -> BOOL
-        );
-        decl.add_method(
-            sel!(application:openTempFile:),
-            open_temp_file::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
-        );
+            // Opening Files
+            decl.add_method(
+                sel!(application:openURLs:),
+                open_urls::<T> as extern "C" fn(&Object, _, _, id)
+            );
+            decl.add_method(
+                sel!(application:openFileWithoutUI:),
+                open_file_without_ui::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
+            );
+            decl.add_method(
+                sel!(applicationShouldOpenUntitledFile:),
+                should_open_untitled_file::<T> as extern "C" fn(&Object, _, _) -> BOOL
+            );
+            decl.add_method(
+                sel!(applicationOpenUntitledFile:),
+                open_untitled_file::<T> as extern "C" fn(&Object, _, _) -> BOOL
+            );
+            decl.add_method(
+                sel!(application:openTempFile:),
+                open_temp_file::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
+            );
 
-        // Printing
-        decl.add_method(
-            sel!(application:printFile:),
-            print_file::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
-        );
-        decl.add_method(
-            sel!(application:printFiles:withSettings:showPrintPanels:),
-            print_files::<T> as extern "C" fn(&Object, _, id, id, id, BOOL) -> NSUInteger
-        );
+            // Printing
+            decl.add_method(
+                sel!(application:printFile:),
+                print_file::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
+            );
+            decl.add_method(
+                sel!(application:printFiles:withSettings:showPrintPanels:),
+                print_files::<T> as extern "C" fn(&Object, _, id, id, id, BOOL) -> NSUInteger
+            );
 
-        // @TODO: Restoring Application State
-        // Depends on NSCoder support, which is... welp.
+            // @TODO: Restoring Application State
+            // Depends on NSCoder support, which is... welp.
 
-        // Scripting
-        decl.add_method(
-            sel!(application:delegateHandlesKey:),
-            delegate_handles_key::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
-        );
+            // Scripting
+            decl.add_method(
+                sel!(application:delegateHandlesKey:),
+                delegate_handles_key::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
+            );
 
-        DELEGATE_CLASS = decl.register();
-    });
+            DELEGATE_CLASS = decl.register();
+        });
+    }
 
     unsafe { DELEGATE_CLASS }
 }
diff --git a/src/appkit/menu/item.rs b/src/appkit/menu/item.rs
index 3f65ed5..334ffa4 100644
--- a/src/appkit/menu/item.rs
+++ b/src/appkit/menu/item.rs
@@ -316,17 +316,22 @@ extern "C" fn fire_block_action(this: &Object, _: Sel, _item: id) {
 pub(crate) fn register_menu_item_class() -> *const Class {
     static mut APP_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "CacaoMenuItem";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSMenuItem);
-        let mut decl = ClassDecl::new("CacaoMenuItem", superclass).unwrap();
-        decl.add_ivar::<usize>(BLOCK_PTR);
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { APP_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSMenuItem);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            decl.add_ivar::<usize>(BLOCK_PTR);
 
-        decl.add_method(sel!(dealloc), dealloc_cacao_menuitem as extern "C" fn(&Object, _));
-        decl.add_method(sel!(fireBlockAction:), fire_block_action as extern "C" fn(&Object, _, id));
+            decl.add_method(sel!(dealloc), dealloc_cacao_menuitem as extern "C" fn(&Object, _));
+            decl.add_method(sel!(fireBlockAction:), fire_block_action as extern "C" fn(&Object, _, id));
 
-        APP_CLASS = decl.register();
-    });
+            APP_CLASS = decl.register();
+        });
+    }
 
     unsafe { APP_CLASS }
 }
diff --git a/src/appkit/window/controller/class.rs b/src/appkit/window/controller/class.rs
index 2f9c914..f82c5d0 100644
--- a/src/appkit/window/controller/class.rs
+++ b/src/appkit/window/controller/class.rs
@@ -14,13 +14,18 @@ use crate::appkit::window::{WindowDelegate, WINDOW_DELEGATE_PTR};
 pub(crate) fn register_window_controller_class<T: WindowDelegate>() -> *const Class {
     static mut DELEGATE_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTWindowController";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSWindowController);
-        let mut decl = ClassDecl::new("RSTWindowController", superclass).unwrap();
-        decl.add_ivar::<usize>(WINDOW_DELEGATE_PTR);
-        DELEGATE_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { DELEGATE_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSWindowController);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            decl.add_ivar::<usize>(WINDOW_DELEGATE_PTR);
+            DELEGATE_CLASS = decl.register();
+        });
+    }
 
     unsafe { DELEGATE_CLASS }
 }
diff --git a/src/button/mod.rs b/src/button/mod.rs
index 822fb5c..979385d 100644
--- a/src/button/mod.rs
+++ b/src/button/mod.rs
@@ -345,12 +345,18 @@ impl Drop for Button {
 fn register_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTButton";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSButton);
-        let decl = ClassDecl::new("RSTButton", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
-
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe {
+            VIEW_CLASS = c;
+        }
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSButton);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            VIEW_CLASS = decl.register();
+        });
+    }
     unsafe { VIEW_CLASS }
 }
diff --git a/src/color/appkit_dynamic_color.rs b/src/color/appkit_dynamic_color.rs
index 6283350..6502614 100644
--- a/src/color/appkit_dynamic_color.rs
+++ b/src/color/appkit_dynamic_color.rs
@@ -261,107 +261,112 @@ extern "C" fn color_with_system_effect(this: &Object, _: Sel, effect: NSInteger)
 pub(crate) fn register_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "CacaoDynamicColor";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSColor);
-        let mut decl = ClassDecl::new("CacaoDynamicColor", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSColor);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        // These methods all need to be forwarded, so let's hook them up.
-        decl.add_method(sel!(colorSpace), color_space as extern "C" fn(&Object, _) -> id);
-        decl.add_method(
-            sel!(colorUsingColorSpace:),
-            color_using_color_space as extern "C" fn(&Object, _, id) -> id
-        );
-        decl.add_method(sel!(colorSpaceName), color_space_name as extern "C" fn(&Object, _) -> id);
-        decl.add_method(
-            sel!(colorUsingColorSpaceName:),
-            color_using_color_space_name as extern "C" fn(&Object, _, id) -> id
-        );
-        decl.add_method(
-            sel!(numberOfComponents),
-            number_of_components as extern "C" fn(&Object, _) -> NSInteger
-        );
+            // These methods all need to be forwarded, so let's hook them up.
+            decl.add_method(sel!(colorSpace), color_space as extern "C" fn(&Object, _) -> id);
+            decl.add_method(
+                sel!(colorUsingColorSpace:),
+                color_using_color_space as extern "C" fn(&Object, _, id) -> id
+            );
+            decl.add_method(sel!(colorSpaceName), color_space_name as extern "C" fn(&Object, _) -> id);
+            decl.add_method(
+                sel!(colorUsingColorSpaceName:),
+                color_using_color_space_name as extern "C" fn(&Object, _, id) -> id
+            );
+            decl.add_method(
+                sel!(numberOfComponents),
+                number_of_components as extern "C" fn(&Object, _) -> NSInteger
+            );
 
-        decl.add_method(sel!(getComponents:), get_components as extern "C" fn(&Object, _, CGFloat));
-        decl.add_method(
-            sel!(getRed:green:blue:alpha:),
-            get_rgba as extern "C" fn(&Object, _, CGFloat, CGFloat, CGFloat, CGFloat)
-        );
-        decl.add_method(sel!(redComponent), red_component as extern "C" fn(&Object, _) -> CGFloat);
-        decl.add_method(sel!(greenComponent), green_component as extern "C" fn(&Object, _) -> CGFloat);
-        decl.add_method(sel!(blueComponent), blue_component as extern "C" fn(&Object, _) -> CGFloat);
+            decl.add_method(sel!(getComponents:), get_components as extern "C" fn(&Object, _, CGFloat));
+            decl.add_method(
+                sel!(getRed:green:blue:alpha:),
+                get_rgba as extern "C" fn(&Object, _, CGFloat, CGFloat, CGFloat, CGFloat)
+            );
+            decl.add_method(sel!(redComponent), red_component as extern "C" fn(&Object, _) -> CGFloat);
+            decl.add_method(sel!(greenComponent), green_component as extern "C" fn(&Object, _) -> CGFloat);
+            decl.add_method(sel!(blueComponent), blue_component as extern "C" fn(&Object, _) -> CGFloat);
 
-        decl.add_method(sel!(hueComponent), hue_component as extern "C" fn(&Object, _) -> CGFloat);
-        decl.add_method(
-            sel!(saturationComponent),
-            saturation_component as extern "C" fn(&Object, _) -> CGFloat
-        );
-        decl.add_method(
-            sel!(brightnessComponent),
-            brightness_component as extern "C" fn(&Object, _) -> CGFloat
-        );
-        decl.add_method(
-            sel!(getHue:saturation:brightness:alpha:),
-            get_hsba as extern "C" fn(&Object, _, CGFloat, CGFloat, CGFloat, CGFloat)
-        );
+            decl.add_method(sel!(hueComponent), hue_component as extern "C" fn(&Object, _) -> CGFloat);
+            decl.add_method(
+                sel!(saturationComponent),
+                saturation_component as extern "C" fn(&Object, _) -> CGFloat
+            );
+            decl.add_method(
+                sel!(brightnessComponent),
+                brightness_component as extern "C" fn(&Object, _) -> CGFloat
+            );
+            decl.add_method(
+                sel!(getHue:saturation:brightness:alpha:),
+                get_hsba as extern "C" fn(&Object, _, CGFloat, CGFloat, CGFloat, CGFloat)
+            );
 
-        decl.add_method(sel!(whiteComponent), white_component as extern "C" fn(&Object, _) -> CGFloat);
-        decl.add_method(
-            sel!(getWhite:alpha:),
-            get_white as extern "C" fn(&Object, _, CGFloat, CGFloat)
-        );
+            decl.add_method(sel!(whiteComponent), white_component as extern "C" fn(&Object, _) -> CGFloat);
+            decl.add_method(
+                sel!(getWhite:alpha:),
+                get_white as extern "C" fn(&Object, _, CGFloat, CGFloat)
+            );
 
-        decl.add_method(sel!(cyanComponent), cyan_component as extern "C" fn(&Object, _) -> CGFloat);
-        decl.add_method(
-            sel!(magentaComponent),
-            magenta_component as extern "C" fn(&Object, _) -> CGFloat
-        );
-        decl.add_method(
-            sel!(yellowComponent),
-            yellow_component as extern "C" fn(&Object, _) -> CGFloat
-        );
-        decl.add_method(sel!(blackComponent), black_component as extern "C" fn(&Object, _) -> CGFloat);
-        decl.add_method(
-            sel!(getCyan:magenta:yellow:black:alpha:),
-            get_cmyk as extern "C" fn(&Object, _, CGFloat, CGFloat, CGFloat, CGFloat, CGFloat)
-        );
+            decl.add_method(sel!(cyanComponent), cyan_component as extern "C" fn(&Object, _) -> CGFloat);
+            decl.add_method(
+                sel!(magentaComponent),
+                magenta_component as extern "C" fn(&Object, _) -> CGFloat
+            );
+            decl.add_method(
+                sel!(yellowComponent),
+                yellow_component as extern "C" fn(&Object, _) -> CGFloat
+            );
+            decl.add_method(sel!(blackComponent), black_component as extern "C" fn(&Object, _) -> CGFloat);
+            decl.add_method(
+                sel!(getCyan:magenta:yellow:black:alpha:),
+                get_cmyk as extern "C" fn(&Object, _, CGFloat, CGFloat, CGFloat, CGFloat, CGFloat)
+            );
 
-        decl.add_method(sel!(alphaComponent), alpha_component as extern "C" fn(&Object, _) -> CGFloat);
+            decl.add_method(sel!(alphaComponent), alpha_component as extern "C" fn(&Object, _) -> CGFloat);
 
-        decl.add_method(sel!(CGColor), cg_color as extern "C" fn(&Object, _) -> id);
-        decl.add_method(sel!(setStroke), set_stroke as extern "C" fn(&Object, _));
-        decl.add_method(sel!(setFill), set_fill as extern "C" fn(&Object, _));
-        decl.add_method(sel!(set), call_set as extern "C" fn(&Object, _));
+            decl.add_method(sel!(CGColor), cg_color as extern "C" fn(&Object, _) -> id);
+            decl.add_method(sel!(setStroke), set_stroke as extern "C" fn(&Object, _));
+            decl.add_method(sel!(setFill), set_fill as extern "C" fn(&Object, _));
+            decl.add_method(sel!(set), call_set as extern "C" fn(&Object, _));
 
-        decl.add_method(
-            sel!(highlightWithLevel:),
-            highlight_with_level as extern "C" fn(&Object, _, CGFloat) -> id
-        );
-        decl.add_method(
-            sel!(shadowWithLevel:),
-            shadow_with_level as extern "C" fn(&Object, _, CGFloat) -> id
-        );
+            decl.add_method(
+                sel!(highlightWithLevel:),
+                highlight_with_level as extern "C" fn(&Object, _, CGFloat) -> id
+            );
+            decl.add_method(
+                sel!(shadowWithLevel:),
+                shadow_with_level as extern "C" fn(&Object, _, CGFloat) -> id
+            );
 
-        decl.add_method(
-            sel!(colorWithAlphaComponent:),
-            color_with_alpha_component as extern "C" fn(&Object, _, CGFloat) -> id
-        );
-        decl.add_method(
-            sel!(blendedColorWithFraction:ofColor:),
-            blended_color as extern "C" fn(&Object, _, CGFloat, id) -> id
-        );
-        decl.add_method(
-            sel!(colorWithSystemEffect:),
-            color_with_system_effect as extern "C" fn(&Object, _, NSInteger) -> id
-        );
+            decl.add_method(
+                sel!(colorWithAlphaComponent:),
+                color_with_alpha_component as extern "C" fn(&Object, _, CGFloat) -> id
+            );
+            decl.add_method(
+                sel!(blendedColorWithFraction:ofColor:),
+                blended_color as extern "C" fn(&Object, _, CGFloat, id) -> id
+            );
+            decl.add_method(
+                sel!(colorWithSystemEffect:),
+                color_with_system_effect as extern "C" fn(&Object, _, NSInteger) -> id
+            );
 
-        decl.add_ivar::<id>(AQUA_LIGHT_COLOR_NORMAL_CONTRAST);
-        decl.add_ivar::<id>(AQUA_LIGHT_COLOR_HIGH_CONTRAST);
-        decl.add_ivar::<id>(AQUA_DARK_COLOR_NORMAL_CONTRAST);
-        decl.add_ivar::<id>(AQUA_DARK_COLOR_HIGH_CONTRAST);
+            decl.add_ivar::<id>(AQUA_LIGHT_COLOR_NORMAL_CONTRAST);
+            decl.add_ivar::<id>(AQUA_LIGHT_COLOR_HIGH_CONTRAST);
+            decl.add_ivar::<id>(AQUA_DARK_COLOR_NORMAL_CONTRAST);
+            decl.add_ivar::<id>(AQUA_DARK_COLOR_HIGH_CONTRAST);
 
-        VIEW_CLASS = decl.register();
-    });
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/image/appkit.rs b/src/image/appkit.rs
index 0dceb69..b388dd2 100644
--- a/src/image/appkit.rs
+++ b/src/image/appkit.rs
@@ -25,15 +25,20 @@ use crate::view::{ViewDelegate, VIEW_DELEGATE_PTR};
 pub(crate) fn register_image_view_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTImageView";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSImageView);
-        let decl = ClassDecl::new("RSTImageView", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSImageView);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        //decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
+            //decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
 
-        VIEW_CLASS = decl.register();
-    });
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/image/uikit.rs b/src/image/uikit.rs
index ef989fe..43acf5d 100644
--- a/src/image/uikit.rs
+++ b/src/image/uikit.rs
@@ -15,12 +15,17 @@ use crate::view::{ViewDelegate, VIEW_DELEGATE_PTR};
 pub(crate) fn register_image_view_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTImageView";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIImageView);
-        let mut decl = ClassDecl::new("RSTImageView", superclass).expect("Failed to get RSTVIEW");
-        VIEW_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(UIImageView);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).expect("Failed to get RSTVIEW");
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/input/appkit.rs b/src/input/appkit.rs
index 2138117..560c14e 100644
--- a/src/input/appkit.rs
+++ b/src/input/appkit.rs
@@ -54,12 +54,17 @@ extern "C" fn text_should_end_editing<T: TextFieldDelegate>(this: &mut Object, _
 pub(crate) fn register_view_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTTextInputField";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSTextField);
-        let decl = ClassDecl::new("RSTTextInputField", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSTextField);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/invoker.rs b/src/invoker.rs
index 26560f2..51ab45f 100644
--- a/src/invoker.rs
+++ b/src/invoker.rs
@@ -97,16 +97,23 @@ extern "C" fn perform<F: Fn() + 'static>(this: &mut Object, _: Sel, _sender: id)
 pub(crate) fn register_invoker_class<F: Fn() + 'static>() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTTargetActionHandler";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSObject);
-        let mut decl = ClassDecl::new("RSTTargetActionHandler", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe {
+            VIEW_CLASS = c;
+        }
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSObject);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        decl.add_ivar::<usize>(ACTION_CALLBACK_PTR);
-        decl.add_method(sel!(perform:), perform::<F> as extern "C" fn(&mut Object, _, id));
+            decl.add_ivar::<usize>(ACTION_CALLBACK_PTR);
+            decl.add_method(sel!(perform:), perform::<F> as extern "C" fn(&mut Object, _, id));
 
-        VIEW_CLASS = decl.register();
-    });
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/listview/appkit.rs b/src/listview/appkit.rs
index f2c0391..95c5fd3 100644
--- a/src/listview/appkit.rs
+++ b/src/listview/appkit.rs
@@ -187,12 +187,17 @@ extern "C" fn dragging_exited<T: ListViewDelegate>(this: &mut Object, _: Sel, in
 pub(crate) fn register_listview_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &'static str = "RSTListView";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSTableView);
-        let decl = ClassDecl::new("RSTListView", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSTableView);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/listview/row/appkit.rs b/src/listview/row/appkit.rs
index d6f4749..25a96e1 100644
--- a/src/listview/row/appkit.rs
+++ b/src/listview/row/appkit.rs
@@ -109,15 +109,20 @@ extern "C" fn dealloc<T: ViewDelegate>(this: &Object, _: Sel) {
 pub(crate) fn register_listview_row_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTTableViewRow";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSView);
-        let mut decl = ClassDecl::new("RSTTableViewRow", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSView);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
+            decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
 
-        VIEW_CLASS = decl.register();
-    });
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
@@ -127,46 +132,51 @@ pub(crate) fn register_listview_row_class() -> *const Class {
 pub(crate) fn register_listview_row_class_with_delegate<T: ViewDelegate>() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTableViewRowWithDelegate";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSView);
-        let mut decl = ClassDecl::new("RSTableViewRowWithDelegate", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSView);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        // A pointer to the "view controller" on the Rust side. It's expected that this doesn't
-        // move.
-        decl.add_ivar::<usize>(LISTVIEW_ROW_DELEGATE_PTR);
-        decl.add_ivar::<id>(BACKGROUND_COLOR);
+            // A pointer to the "view controller" on the Rust side. It's expected that this doesn't
+            // move.
+            decl.add_ivar::<usize>(LISTVIEW_ROW_DELEGATE_PTR);
+            decl.add_ivar::<id>(BACKGROUND_COLOR);
 
-        decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
-        decl.add_method(sel!(updateLayer), update_layer as extern "C" fn(&Object, _));
+            decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
+            decl.add_method(sel!(updateLayer), update_layer as extern "C" fn(&Object, _));
 
-        // Drag and drop operations (e.g, accepting files)
-        decl.add_method(
-            sel!(draggingEntered:),
-            dragging_entered::<T> as extern "C" fn(&mut Object, _, _) -> NSUInteger
-        );
-        decl.add_method(
-            sel!(prepareForDragOperation:),
-            prepare_for_drag_operation::<T> as extern "C" fn(&mut Object, _, _) -> BOOL
-        );
-        decl.add_method(
-            sel!(performDragOperation:),
-            perform_drag_operation::<T> as extern "C" fn(&mut Object, _, _) -> BOOL
-        );
-        decl.add_method(
-            sel!(concludeDragOperation:),
-            conclude_drag_operation::<T> as extern "C" fn(&mut Object, _, _)
-        );
-        decl.add_method(
-            sel!(draggingExited:),
-            dragging_exited::<T> as extern "C" fn(&mut Object, _, _)
-        );
+            // Drag and drop operations (e.g, accepting files)
+            decl.add_method(
+                sel!(draggingEntered:),
+                dragging_entered::<T> as extern "C" fn(&mut Object, _, _) -> NSUInteger
+            );
+            decl.add_method(
+                sel!(prepareForDragOperation:),
+                prepare_for_drag_operation::<T> as extern "C" fn(&mut Object, _, _) -> BOOL
+            );
+            decl.add_method(
+                sel!(performDragOperation:),
+                perform_drag_operation::<T> as extern "C" fn(&mut Object, _, _) -> BOOL
+            );
+            decl.add_method(
+                sel!(concludeDragOperation:),
+                conclude_drag_operation::<T> as extern "C" fn(&mut Object, _, _)
+            );
+            decl.add_method(
+                sel!(draggingExited:),
+                dragging_exited::<T> as extern "C" fn(&mut Object, _, _)
+            );
 
-        // Cleanup
-        decl.add_method(sel!(dealloc), dealloc::<T> as extern "C" fn(&Object, _));
+            // Cleanup
+            decl.add_method(sel!(dealloc), dealloc::<T> as extern "C" fn(&Object, _));
 
-        VIEW_CLASS = decl.register();
-    });
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/listview/row/uikit.rs b/src/listview/row/uikit.rs
index 1e835ed..1ea8ce4 100644
--- a/src/listview/row/uikit.rs
+++ b/src/listview/row/uikit.rs
@@ -16,12 +16,17 @@ use crate::utils::load;
 pub(crate) fn register_view_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTView";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIView);
-        let mut decl = ClassDecl::new("RSTView", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(UIView);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
@@ -31,15 +36,18 @@ pub(crate) fn register_view_class() -> *const Class {
 pub(crate) fn register_view_class_with_delegate<T: ViewDelegate>() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTViewWithDelegate";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIView);
-        let mut decl = ClassDecl::new("RSTViewWithDelegate", superclass).unwrap();
-        decl.add_ivar::<usize>(VIEW_DELEGATE_PTR);
-        VIEW_CLASS = decl.register();
-    });
-
-    unsafe {
-        VIEW_CLASS
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(UIView);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            decl.add_ivar::<usize>(VIEW_DELEGATE_PTR);
+            VIEW_CLASS = decl.register();
+        });
     }
+
+    unsafe { VIEW_CLASS }
 }
diff --git a/src/scrollview/appkit.rs b/src/scrollview/appkit.rs
index f686f20..d325465 100644
--- a/src/scrollview/appkit.rs
+++ b/src/scrollview/appkit.rs
@@ -79,12 +79,17 @@ extern "C" fn dragging_exited<T: ScrollViewDelegate>(this: &mut Object, _: Sel,
 pub(crate) fn register_scrollview_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &'static str = "RSTScrollView";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSScrollView);
-        let decl = ClassDecl::new("RSTScrollView", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSScrollView);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
@@ -94,41 +99,46 @@ pub(crate) fn register_scrollview_class() -> *const Class {
 pub(crate) fn register_scrollview_class_with_delegate<T: ScrollViewDelegate>() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &'static str = "RSTScrollViewWithDelegate";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSScrollView);
-        let mut decl = ClassDecl::new("RSTScrollViewWithDelegate", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSScrollView);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        // A pointer to the "view controller" on the Rust side. It's expected that this doesn't
-        // move.
-        decl.add_ivar::<usize>(SCROLLVIEW_DELEGATE_PTR);
+            // A pointer to the "view controller" on the Rust side. It's expected that this doesn't
+            // move.
+            decl.add_ivar::<usize>(SCROLLVIEW_DELEGATE_PTR);
 
-        decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
+            decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
 
-        // Drag and drop operations (e.g, accepting files)
-        decl.add_method(
-            sel!(draggingEntered:),
-            dragging_entered::<T> as extern "C" fn(&mut Object, _, _) -> NSUInteger
-        );
-        decl.add_method(
-            sel!(prepareForDragOperation:),
-            prepare_for_drag_operation::<T> as extern "C" fn(&mut Object, _, _) -> BOOL
-        );
-        decl.add_method(
-            sel!(performDragOperation:),
-            perform_drag_operation::<T> as extern "C" fn(&mut Object, _, _) -> BOOL
-        );
-        decl.add_method(
-            sel!(concludeDragOperation:),
-            conclude_drag_operation::<T> as extern "C" fn(&mut Object, _, _)
-        );
-        decl.add_method(
-            sel!(draggingExited:),
-            dragging_exited::<T> as extern "C" fn(&mut Object, _, _)
-        );
+            // Drag and drop operations (e.g, accepting files)
+            decl.add_method(
+                sel!(draggingEntered:),
+                dragging_entered::<T> as extern "C" fn(&mut Object, _, _) -> NSUInteger
+            );
+            decl.add_method(
+                sel!(prepareForDragOperation:),
+                prepare_for_drag_operation::<T> as extern "C" fn(&mut Object, _, _) -> BOOL
+            );
+            decl.add_method(
+                sel!(performDragOperation:),
+                perform_drag_operation::<T> as extern "C" fn(&mut Object, _, _) -> BOOL
+            );
+            decl.add_method(
+                sel!(concludeDragOperation:),
+                conclude_drag_operation::<T> as extern "C" fn(&mut Object, _, _)
+            );
+            decl.add_method(
+                sel!(draggingExited:),
+                dragging_exited::<T> as extern "C" fn(&mut Object, _, _)
+            );
 
-        VIEW_CLASS = decl.register();
-    });
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/select/mod.rs b/src/select/mod.rs
index 7eab27d..2cbdd2e 100644
--- a/src/select/mod.rs
+++ b/src/select/mod.rs
@@ -270,12 +270,17 @@ impl Drop for Select {
 fn register_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "CacaoSelect";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSPopUpButton);
-        let decl = ClassDecl::new("CacaoSelect", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSPopUpButton);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/switch.rs b/src/switch.rs
index eab6b38..5d04c87 100644
--- a/src/switch.rs
+++ b/src/switch.rs
@@ -180,12 +180,19 @@ impl Drop for Switch {
 fn register_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTSwitch";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSButton);
-        let decl = ClassDecl::new("RSTSwitch", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe {
+            VIEW_CLASS = c;
+        }
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSButton);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/text/label/appkit.rs b/src/text/label/appkit.rs
index 1b3b681..e27fe1b 100644
--- a/src/text/label/appkit.rs
+++ b/src/text/label/appkit.rs
@@ -25,12 +25,17 @@ use crate::utils::load;
 pub(crate) fn register_view_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTTextField";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSTextField);
-        let decl = ClassDecl::new("RSTTextField", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSTextField);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
@@ -40,17 +45,22 @@ pub(crate) fn register_view_class() -> *const Class {
 pub(crate) fn register_view_class_with_delegate<T: LabelDelegate>() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTTextFieldWithDelegate";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSView);
-        let mut decl = ClassDecl::new("RSTTextFieldWithDelegate", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSView);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        // A pointer to the "view controller" on the Rust side. It's expected that this doesn't
-        // move.
-        decl.add_ivar::<usize>(LABEL_DELEGATE_PTR);
+            // A pointer to the "view controller" on the Rust side. It's expected that this doesn't
+            // move.
+            decl.add_ivar::<usize>(LABEL_DELEGATE_PTR);
 
-        VIEW_CLASS = decl.register();
-    });
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/uikit/app/class.rs b/src/uikit/app/class.rs
index 3baf350..37909f0 100644
--- a/src/uikit/app/class.rs
+++ b/src/uikit/app/class.rs
@@ -12,12 +12,17 @@ use objc::runtime::Class;
 pub(crate) fn register_app_class() -> *const Class {
     static mut APP_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTApplication";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIApplication);
-        let decl = ClassDecl::new("RSTApplication", superclass).unwrap();
-        APP_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { APP_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(UIApplication);
+            let decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            APP_CLASS = decl.register();
+        });
+    }
 
     unsafe { APP_CLASS }
 }
diff --git a/src/uikit/app/delegate.rs b/src/uikit/app/delegate.rs
index aba45ed..5462b69 100644
--- a/src/uikit/app/delegate.rs
+++ b/src/uikit/app/delegate.rs
@@ -51,29 +51,34 @@ extern "C" fn configuration_for_scene_session<T: AppDelegate>(this: &Object, _:
 pub(crate) fn register_app_delegate_class<T: AppDelegate>() -> *const Class {
     static mut DELEGATE_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTAppDelegate";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSObject);
-        let mut decl = ClassDecl::new("RSTAppDelegate", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { DELEGATE_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSObject);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        // Launching Applications
-        decl.add_method(
-            sel!(application:didFinishLaunchingWithOptions:),
-            did_finish_launching::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
-        );
+            // Launching Applications
+            decl.add_method(
+                sel!(application:didFinishLaunchingWithOptions:),
+                did_finish_launching::<T> as extern "C" fn(&Object, _, _, id) -> BOOL
+            );
 
-        // Scenes
-        decl.add_method(
-            sel!(application:configurationForConnectingSceneSession:options:),
-            configuration_for_scene_session::<T> as extern "C" fn(&Object, _, _, id, id) -> id
-        );
-        /*decl.add_method(
-            sel!(application:didDiscardSceneSessions:),
-            did_discard_scene_sessions::<T> as extern "C" fn(&Object, _, _, id)
-        );*/
+            // Scenes
+            decl.add_method(
+                sel!(application:configurationForConnectingSceneSession:options:),
+                configuration_for_scene_session::<T> as extern "C" fn(&Object, _, _, id, id) -> id
+            );
+            /*decl.add_method(
+                sel!(application:didDiscardSceneSessions:),
+                did_discard_scene_sessions::<T> as extern "C" fn(&Object, _, _, id)
+            );*/
 
-        DELEGATE_CLASS = decl.register();
-    });
+            DELEGATE_CLASS = decl.register();
+        });
+    }
 
     unsafe { DELEGATE_CLASS }
 }
diff --git a/src/uikit/scene/delegate.rs b/src/uikit/scene/delegate.rs
index 75aa69a..2406f84 100644
--- a/src/uikit/scene/delegate.rs
+++ b/src/uikit/scene/delegate.rs
@@ -62,30 +62,35 @@ extern "C" fn scene_will_connect_to_session_with_options<T: WindowSceneDelegate>
 pub(crate) fn register_window_scene_delegate_class<T: WindowSceneDelegate, F: Fn() -> Box<T>>() -> *const Class {
     static mut DELEGATE_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTWindowSceneDelegate";
 
-    use objc::runtime::{class_addProtocol, Protocol};
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIResponder);
-        let mut decl = ClassDecl::new("RSTWindowSceneDelegate", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { DELEGATE_CLASS = c };
+    } else {
+        use objc::runtime::Protocol;
+        INIT.call_once(|| unsafe {
+            let superclass = class!(UIResponder);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        let p = Protocol::get("UIWindowSceneDelegate").unwrap();
+            let p = Protocol::get("UIWindowSceneDelegate").unwrap();
 
-        // A spot to hold a pointer to
-        decl.add_ivar::<usize>(WINDOW_SCENE_PTR);
-        decl.add_protocol(p);
+            // A spot to hold a pointer to
+            decl.add_ivar::<usize>(WINDOW_SCENE_PTR);
+            decl.add_protocol(p);
 
-        // Override the `init` call to handle creating and attaching a WindowSceneDelegate.
-        decl.add_method(sel!(init), init::<T, F> as extern "C" fn(&mut Object, _) -> id);
+            // Override the `init` call to handle creating and attaching a WindowSceneDelegate.
+            decl.add_method(sel!(init), init::<T, F> as extern "C" fn(&mut Object, _) -> id);
 
-        // UIWindowSceneDelegate API
-        decl.add_method(
-            sel!(scene:willConnectToSession:options:),
-            scene_will_connect_to_session_with_options::<T> as extern "C" fn(&Object, _, _, _, _)
-        );
+            // UIWindowSceneDelegate API
+            decl.add_method(
+                sel!(scene:willConnectToSession:options:),
+                scene_will_connect_to_session_with_options::<T> as extern "C" fn(&Object, _, _, _, _)
+            );
 
-        // Launching Applications
-        DELEGATE_CLASS = decl.register();
-    });
+            // Launching Applications
+            DELEGATE_CLASS = decl.register();
+        });
+    }
 
     unsafe { DELEGATE_CLASS }
 }
diff --git a/src/view/appkit.rs b/src/view/appkit.rs
index 27b047e..85bc096 100644
--- a/src/view/appkit.rs
+++ b/src/view/appkit.rs
@@ -94,19 +94,24 @@ extern "C" fn update_layer(this: &Object, _: Sel) {
 pub(crate) fn register_view_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTView";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(NSView);
-        let mut decl = ClassDecl::new("RSTView", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(NSView);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
-        decl.add_method(sel!(updateLayer), update_layer as extern "C" fn(&Object, _));
-        decl.add_method(sel!(wantsUpdateLayer), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
+            decl.add_method(sel!(isFlipped), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
+            decl.add_method(sel!(updateLayer), update_layer as extern "C" fn(&Object, _));
+            decl.add_method(sel!(wantsUpdateLayer), enforce_normalcy as extern "C" fn(&Object, _) -> BOOL);
 
-        decl.add_ivar::<id>(BACKGROUND_COLOR);
+            decl.add_ivar::<id>(BACKGROUND_COLOR);
 
-        VIEW_CLASS = decl.register();
-    });
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/view/splitviewcontroller/ios.rs b/src/view/splitviewcontroller/ios.rs
index fe2ab7b..bb4cf59 100644
--- a/src/view/splitviewcontroller/ios.rs
+++ b/src/view/splitviewcontroller/ios.rs
@@ -53,20 +53,30 @@ extern "C" fn did_disappear<T: ViewDelegate>(this: &mut Object, _: Sel, animated
 pub(crate) fn register_view_controller_class<T: ViewDelegate + 'static>() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTViewController";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIViewController);
-        let mut decl = ClassDecl::new("RSTViewController", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(UIViewController);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
 
-        decl.add_ivar::<usize>(VIEW_DELEGATE_PTR);
+            decl.add_ivar::<usize>(VIEW_DELEGATE_PTR);
 
-        decl.add_method(sel!(viewWillAppear:), will_appear::<T> as extern "C" fn(&mut Object, _, BOOL));
-        decl.add_method(sel!(viewDidAppear:), did_appear::<T> as extern "C" fn(&mut Object, _, BOOL));
-        decl.add_method(sel!(viewWillDisappear:), will_disappear::<T> as extern "C" fn(&mut Object, _, BOOL));
-        decl.add_method(sel!(viewDidDisappear:), did_disappear::<T> as extern "C" fn(&mut Object, _, BOOL));
-
-        VIEW_CLASS = decl.register();
-    });
+            decl.add_method(sel!(viewWillAppear:), will_appear::<T> as extern "C" fn(&mut Object, _, BOOL));
+            decl.add_method(sel!(viewDidAppear:), did_appear::<T> as extern "C" fn(&mut Object, _, BOOL));
+            decl.add_method(
+                sel!(viewWillDisappear:),
+                will_disappear::<T> as extern "C" fn(&mut Object, _, BOOL)
+            );
+            decl.add_method(
+                sel!(viewDidDisappear:),
+                did_disappear::<T> as extern "C" fn(&mut Object, _, BOOL)
+            );
 
+            VIEW_CLASS = decl.register();
+        });
+    }
     unsafe { VIEW_CLASS }
 }
diff --git a/src/view/uikit.rs b/src/view/uikit.rs
index 4b697d9..54015ce 100644
--- a/src/view/uikit.rs
+++ b/src/view/uikit.rs
@@ -16,12 +16,17 @@ use crate::view::{ViewDelegate, VIEW_DELEGATE_PTR};
 pub(crate) fn register_view_class() -> *const Class {
     static mut VIEW_CLASS: *const Class = 0 as *const Class;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTView";
 
-    INIT.call_once(|| unsafe {
-        let superclass = class!(UIView);
-        let mut decl = ClassDecl::new("RSTView", superclass).unwrap();
-        VIEW_CLASS = decl.register();
-    });
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { VIEW_CLASS = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = class!(UIView);
+            let mut decl = ClassDecl::new(CLASS_NAME, superclass).unwrap();
+            VIEW_CLASS = decl.register();
+        });
+    }
 
     unsafe { VIEW_CLASS }
 }
diff --git a/src/webview/process_pool.rs b/src/webview/process_pool.rs
index 8b5c630..718b292 100644
--- a/src/webview/process_pool.rs
+++ b/src/webview/process_pool.rs
@@ -28,17 +28,22 @@ extern "C" fn download_delegate(this: &Object, _: Sel) -> id {
 pub fn register_process_pool() -> *const Object {
     static mut PROCESS_POOL: *const Object = 0 as *const Object;
     static INIT: Once = Once::new();
+    const CLASS_NAME: &str = "RSTWebViewProcessPool";
 
-    INIT.call_once(|| unsafe {
-        let superclass = Class::get("WKProcessPool").unwrap();
-        let mut decl = ClassDecl::new("RSTWebViewProcessPool", superclass).unwrap();
+    if let Some(c) = Class::get(CLASS_NAME) {
+        unsafe { PROCESS_POOL = c };
+    } else {
+        INIT.call_once(|| unsafe {
+            let superclass = Class::get("WKProcessPool").unwrap();
+            let mut decl = ClassDecl::new("RSTWebViewProcessPool", superclass).unwrap();
 
-        //decl.add_ivar::<id>(DOWNLOAD_DELEGATE_PTR);
-        decl.add_method(sel!(_downloadDelegate), download_delegate as extern "C" fn(&Object, _) -> id);
+            //decl.add_ivar::<id>(DOWNLOAD_DELEGATE_PTR);
+            decl.add_method(sel!(_downloadDelegate), download_delegate as extern "C" fn(&Object, _) -> id);
 
-        //PROCESS_POOL = decl.register();
-        PROCESS_POOL = msg_send![decl.register(), new];
-    });
+            //PROCESS_POOL = decl.register();
+            PROCESS_POOL = msg_send![decl.register(), new];
+        });
+    }
 
     unsafe { PROCESS_POOL }
 }