diff --git a/glfw/glfw3.h b/glfw/glfw3.h
index e21576862..d5d746bd8 100644
--- a/glfw/glfw3.h
+++ b/glfw/glfw3.h
@@ -99,8 +99,8 @@ extern "C" {
 /* It is customary to use APIENTRY for OpenGL function pointer declarations on
  * all platforms.  Additionally, the Windows OpenGL header needs APIENTRY.
  */
-#ifndef APIENTRY
- #ifdef _WIN32
+#if !defined(APIENTRY)
+ #if defined(_WIN32)
   #define APIENTRY __stdcall
  #else
   #define APIENTRY