diff --git a/wxPython/contrib/glcanvas/msw/myglcanvas.cpp b/wxPython/contrib/glcanvas/msw/myglcanvas.cpp
index 17bb10e020..196d6734f3 100644
--- a/wxPython/contrib/glcanvas/msw/myglcanvas.cpp
+++ b/wxPython/contrib/glcanvas/msw/myglcanvas.cpp
@@ -22,7 +22,7 @@
 #include <wx/setup.h>
 
 
-
+#undef wxUSE_GLCANVAS
 #define wxUSE_GLCANVAS 1
 #if wxUSE_GLCANVAS
 
diff --git a/wxPython/contrib/glcanvas/msw/myglcanvas.h b/wxPython/contrib/glcanvas/msw/myglcanvas.h
index 2ec721c66b..a56cdb6659 100644
--- a/wxPython/contrib/glcanvas/msw/myglcanvas.h
+++ b/wxPython/contrib/glcanvas/msw/myglcanvas.h
@@ -19,6 +19,7 @@
 #include <wx/setup.h>
 
 
+#undef wxUSE_GLCANVAS
 #define wxUSE_GLCANVAS 1
 #if wxUSE_GLCANVAS