diff --git a/gdk/macos/gdkmacosglcontext.c b/gdk/macos/gdkmacosglcontext.c
index 00ddfefcde..8f7f317cec 100644
--- a/gdk/macos/gdkmacosglcontext.c
+++ b/gdk/macos/gdkmacosglcontext.c
@@ -101,7 +101,7 @@ create_pixel_format (int      major,
     NSOpenGLPFAAccelerated,
     NSOpenGLPFADoubleBuffer,
     NSOpenGLPFABackingStore,
-    NSOpenGLPFAColorSize, 32,
+    NSOpenGLPFAColorSize, 24,
     NSOpenGLPFAAlphaSize, 8,
 
     (NSOpenGLPixelFormatAttribute)nil