diff --git a/Cocoa/GBViewGL.m b/Cocoa/GBViewGL.m
index 15aed08..b80973e 100644
--- a/Cocoa/GBViewGL.m
+++ b/Cocoa/GBViewGL.m
@@ -27,6 +27,7 @@
 {
     [super flip];
     dispatch_async(dispatch_get_main_queue(), ^{
+        [self.internalView setNeedsDisplay:YES];
         [self setNeedsDisplay:YES];
     });
 }