diff --git a/include/GLFW/glfw3.h b/include/GLFW/glfw3.h
index 1b93a3eb..64d797db 100644
--- a/include/GLFW/glfw3.h
+++ b/include/GLFW/glfw3.h
@@ -133,10 +133,38 @@ extern "C" {
 
 /* Most GL/glu.h variants on Windows need wchar_t
  * OpenGL/gl.h blocks the definition of ptrdiff_t by glext.h on OS X */
-#include <stddef.h>
+#if !defined(GLFW_INCLUDE_NONE)
+ #include <stddef.h>
+#endif
 
-
-/* ---------------- GLFW related system specific defines ----------------- */
+/* Include the chosen client API headers.
+ */
+#if defined(__APPLE_CC__)
+  #if defined(GLFW_INCLUDE_GLCOREARB)
+    #include <OpenGL/gl3.h>
+  #elif !defined(GLFW_INCLUDE_NONE)
+    #define GL_GLEXT_LEGACY
+    #include <OpenGL/gl.h>
+  #endif
+  #if defined(GLFW_INCLUDE_GLU)
+    #include <OpenGL/glu.h>
+  #endif
+#else
+  #if defined(GLFW_INCLUDE_GLCOREARB)
+    #include <GL/glcorearb.h>
+  #elif defined(GLFW_INCLUDE_ES1)
+    #include <GLES/gl.h>
+  #elif defined(GLFW_INCLUDE_ES2)
+    #include <GLES2/gl2.h>
+  #elif defined(GLFW_INCLUDE_ES3)
+    #include <GLES3/gl3.h>
+  #elif !defined(GLFW_INCLUDE_NONE)
+    #include <GL/gl.h>
+  #endif
+  #if defined(GLFW_INCLUDE_GLU)
+    #include <GL/glu.h>
+  #endif
+#endif
 
 #if defined(GLFW_DLL) && defined(_GLFW_BUILD_DLL)
  /* GLFW_DLL is defined by users of GLFW when compiling programs that will link
@@ -173,35 +201,6 @@ extern "C" {
 
 /* -------------------- END SYSTEM/COMPILER SPECIFIC --------------------- */
 
-/* Include the chosen client API headers.
- */
-#if defined(__APPLE_CC__)
-  #if defined(GLFW_INCLUDE_GLCOREARB)
-    #include <OpenGL/gl3.h>
-  #elif !defined(GLFW_INCLUDE_NONE)
-    #define GL_GLEXT_LEGACY
-    #include <OpenGL/gl.h>
-  #endif
-  #if defined(GLFW_INCLUDE_GLU)
-    #include <OpenGL/glu.h>
-  #endif
-#else
-  #if defined(GLFW_INCLUDE_GLCOREARB)
-    #include <GL/glcorearb.h>
-  #elif defined(GLFW_INCLUDE_ES1)
-    #include <GLES/gl.h>
-  #elif defined(GLFW_INCLUDE_ES2)
-    #include <GLES2/gl2.h>
-  #elif defined(GLFW_INCLUDE_ES3)
-    #include <GLES3/gl3.h>
-  #elif !defined(GLFW_INCLUDE_NONE)
-    #include <GL/gl.h>
-  #endif
-  #if defined(GLFW_INCLUDE_GLU)
-    #include <GL/glu.h>
-  #endif
-#endif
-
 
 /*************************************************************************
  * GLFW API tokens