diff --git a/Cargo.toml b/Cargo.toml
index bc971705..4f736360 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "glutin"
-version = "0.1.5"
+version = "0.1.6"
 authors = ["tomaka <pierre.krieger1708@gmail.com>"]
 description = "Cross-plaform OpenGL context provider."
 keywords = ["windowing", "opengl"]
diff --git a/src/api/x11/window.rs b/src/api/x11/window.rs
index 4582c3ed..38838f5e 100644
--- a/src/api/x11/window.rs
+++ b/src/api/x11/window.rs
@@ -202,7 +202,7 @@ impl<'a> Iterator for PollEventsIterator<'a> {
                         (self.window.x.display.xlib.XKeycodeToKeysym)(self.window.x.display.display, event.keycode as ffi::KeyCode, 0)
                     };
 
-                    if (ffi::XK_KP_Space as u64 <= keysym) && (keysym <= ffi::XK_KP_9 as u64) {
+                    if (ffi::XK_KP_Space as libc::c_ulong <= keysym) && (keysym <= ffi::XK_KP_9 as libc::c_ulong) {
                         keysym = kp_keysym
                     };