diff --git a/Modules/cstubs b/Modules/cstubs
index cf301f98d33..87864c61a95 100644
--- a/Modules/cstubs
+++ b/Modules/cstubs
@@ -808,6 +808,7 @@ void	RGBmode
 void	singlebuffer
 void	swapbuffers
 void	gsync
+void	gflush
 void	tpon
 void	tpoff
 void	clkon