diff --git a/pens/main/oglpen.c b/pens/main/oglpen.c
index 5ce4bef656..c12218be4e 100644
--- a/pens/main/oglpen.c
+++ b/pens/main/oglpen.c
@@ -18,6 +18,7 @@
 */
 
 #ifdef __APPLE__
+#define GL_SILENCE_DEPRECATION
 #include <OpenGL/glu.h>
 #include <GLUT/glut.h>
 #else