diff --git a/wxPython/contrib/glcanvas/glcanvas.i b/wxPython/contrib/glcanvas/glcanvas.i
index e32d0586de..f1f23d3fad 100644
--- a/wxPython/contrib/glcanvas/glcanvas.i
+++ b/wxPython/contrib/glcanvas/glcanvas.i
@@ -15,6 +15,11 @@
 
 %{
 #include "wxPython.h"
+
+#ifdef __WXMAC__  // avoid a bug in Carbon headers
+#define scalb scalbn
+#endif
+
 #ifdef __WXMSW__
 #include "myglcanvas.h"
 #else