diff --git a/examples/win32_gdi/main.c b/examples/win32_gdi/main.c
index 03ff247..218042c 100644
--- a/examples/win32_gdi/main.c
+++ b/examples/win32_gdi/main.c
@@ -27,8 +27,12 @@ long lastMsgTime = 0;
 bool ui_debug_mode;
 HFONT fonts[1];
 
+#ifndef RECTWIDTH
 #define RECTWIDTH(rc)   ((rc).right - (rc).left)
+#endif
+#ifndef RECTHEIGHT
 #define RECTHEIGHT(rc)  ((rc).bottom - (rc).top)
+#endif
 
 LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
 {
diff --git a/renderers/win32_gdi/clay_renderer_gdi.c b/renderers/win32_gdi/clay_renderer_gdi.c
index ab99524..cc77c11 100644
--- a/renderers/win32_gdi/clay_renderer_gdi.c
+++ b/renderers/win32_gdi/clay_renderer_gdi.c
@@ -11,8 +11,12 @@ HBITMAP renderer_hbmMem = {0};
 HANDLE renderer_hOld = {0};
 bool gdi_fabulous = true;
 
+#ifndef RECTWIDTH
 #define RECTWIDTH(rc)   ((rc).right - (rc).left)
+#endif
+#ifndef RECTHEIGHT
 #define RECTHEIGHT(rc)  ((rc).bottom - (rc).top)
+#endif
 
 /*----------------------------------------------------------------------------+
  | Math stuff start                                                           |