diff --git a/freeglut/freeglut/src/mswin/fg_main_mswin.c b/freeglut/freeglut/src/mswin/fg_main_mswin.c
index c9c0ccf..ea56131 100644
--- a/freeglut/freeglut/src/mswin/fg_main_mswin.c
+++ b/freeglut/freeglut/src/mswin/fg_main_mswin.c
@@ -663,6 +663,7 @@ LRESULT CALLBACK fgPlatformWindowProc( HWND hWnd, UINT uMsg, WPARAM wParam, LPAR
             fghRedrawWindow( window );
             EndPaint( hWnd, &ps );
         }
+        lRet = 0;   /* As per docs, should return 0 */
     }
     break;