diff --git a/ash/src/device.rs b/ash/src/device.rs
index 426fa16..0093e44 100644
--- a/ash/src/device.rs
+++ b/ash/src/device.rs
@@ -328,6 +328,7 @@ impl Device {
             &mut count,
             out.as_mut_ptr(),
         );
+        assert_eq!(count as usize, out.len());
     }
 
     #[doc = "<https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/vkTrimCommandPool.html>"]
diff --git a/ash/src/extensions/khr/get_memory_requirements2.rs b/ash/src/extensions/khr/get_memory_requirements2.rs
index dc15119..8b2547d 100644
--- a/ash/src/extensions/khr/get_memory_requirements2.rs
+++ b/ash/src/extensions/khr/get_memory_requirements2.rs
@@ -70,6 +70,7 @@ impl GetMemoryRequirements2 {
             &mut count,
             out.as_mut_ptr(),
         );
+        assert_eq!(count as usize, out.len());
     }
 
     pub fn name() -> &'static CStr {
diff --git a/ash/src/extensions/khr/get_physical_device_properties2.rs b/ash/src/extensions/khr/get_physical_device_properties2.rs
index 268d67d..29d17fd 100644
--- a/ash/src/extensions/khr/get_physical_device_properties2.rs
+++ b/ash/src/extensions/khr/get_physical_device_properties2.rs
@@ -107,6 +107,7 @@ impl GetPhysicalDeviceProperties2 {
             &mut count,
             out.as_mut_ptr(),
         );
+        assert_eq!(count as usize, out.len());
     }
 
     /// Retrieve the number of elements to pass to [`Self::get_physical_device_sparse_image_format_properties2()`]
@@ -144,6 +145,7 @@ impl GetPhysicalDeviceProperties2 {
                 &mut count,
                 out.as_mut_ptr(),
             );
+        assert_eq!(count as usize, out.len());
     }
 
     pub fn name() -> &'static CStr {
diff --git a/ash/src/extensions/khr/get_surface_capabilities2.rs b/ash/src/extensions/khr/get_surface_capabilities2.rs
index 8c93219..683013b 100644
--- a/ash/src/extensions/khr/get_surface_capabilities2.rs
+++ b/ash/src/extensions/khr/get_surface_capabilities2.rs
@@ -66,7 +66,7 @@ impl GetSurfaceCapabilities2 {
             &mut count,
             out.as_mut_ptr(),
         );
-        assert_eq!(count, out.len() as u32);
+        assert_eq!(count as usize, out.len());
         err_code.result()
     }
 
diff --git a/ash/src/extensions/khr/maintenance4.rs b/ash/src/extensions/khr/maintenance4.rs
index 5f234e0..a3f606f 100644
--- a/ash/src/extensions/khr/maintenance4.rs
+++ b/ash/src/extensions/khr/maintenance4.rs
@@ -69,7 +69,7 @@ impl Maintenance4 {
             &mut count,
             out.as_mut_ptr(),
         );
-        assert_eq!(count, out.len() as u32);
+        assert_eq!(count as usize, out.len());
     }
 
     pub fn name() -> &'static CStr {
diff --git a/ash/src/instance.rs b/ash/src/instance.rs
index 1ea464e..87064c7 100644
--- a/ash/src/instance.rs
+++ b/ash/src/instance.rs
@@ -67,10 +67,12 @@ impl Instance {
         &self,
         out: &mut [vk::PhysicalDeviceGroupProperties],
     ) -> VkResult<()> {
-        let mut group_count = out.len() as u32;
+        let mut count = out.len() as u32;
         self.instance_fn_1_1
-            .enumerate_physical_device_groups(self.handle(), &mut group_count, out.as_mut_ptr())
-            .result()
+            .enumerate_physical_device_groups(self.handle(), &mut count, out.as_mut_ptr())
+            .result()?;
+        assert_eq!(count as usize, out.len());
+        Ok(())
     }
 
     #[doc = "<https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/vkGetPhysicalDeviceFeatures2.html>"]
@@ -144,13 +146,14 @@ impl Instance {
         physical_device: vk::PhysicalDevice,
         out: &mut [vk::QueueFamilyProperties2],
     ) {
-        let mut queue_count = out.len() as u32;
+        let mut count = out.len() as u32;
         self.instance_fn_1_1
             .get_physical_device_queue_family_properties2(
                 physical_device,
-                &mut queue_count,
+                &mut count,
                 out.as_mut_ptr(),
             );
+        assert_eq!(count as usize, out.len());
     }
 
     #[doc = "<https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/vkGetPhysicalDeviceMemoryProperties2.html>"]
@@ -190,14 +193,15 @@ impl Instance {
         format_info: &vk::PhysicalDeviceSparseImageFormatInfo2,
         out: &mut [vk::SparseImageFormatProperties2],
     ) {
-        let mut format_count = out.len() as u32;
+        let mut count = out.len() as u32;
         self.instance_fn_1_1
             .get_physical_device_sparse_image_format_properties2(
                 physical_device,
                 format_info,
-                &mut format_count,
+                &mut count,
                 out.as_mut_ptr(),
             );
+        assert_eq!(count as usize, out.len());
     }
 
     #[doc = "<https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/vkGetPhysicalDeviceExternalBufferProperties.html>"]