diff --git a/src/win32_platform.h b/src/win32_platform.h
index 5e64abcd0..e329c4933 100644
--- a/src/win32_platform.h
+++ b/src/win32_platform.h
@@ -89,6 +89,9 @@
 #ifndef WM_DPICHANGED
  #define WM_DPICHANGED 0x02E0
 #endif
+#ifndef GET_XBUTTON_WPARAM
+ #define GET_XBUTTON_WPARAM(w) (HIWORD(w))
+#endif
 
 #if WINVER < 0x0601
 typedef struct tagCHANGEFILTERSTRUCT
diff --git a/src/win32_window.c b/src/win32_window.c
index 1f58ce6c1..2b34a1ce6 100644
--- a/src/win32_window.c
+++ b/src/win32_window.c
@@ -37,10 +37,6 @@
 
 #define _GLFW_WNDCLASSNAME L"GLFW30"
 
-#ifndef GET_XBUTTON_WPARAM
-#define GET_XBUTTON_WPARAM(w) (HIWORD(w))
-#endif
-
 // Returns the window style for the specified window
 //
 static DWORD getWindowStyle(const _GLFWwindow* window)