diff --git a/direct/src/plugin/p3dMainObject.cxx b/direct/src/plugin/p3dMainObject.cxx
index 07ee45897e..56a7f925e2 100644
--- a/direct/src/plugin/p3dMainObject.cxx
+++ b/direct/src/plugin/p3dMainObject.cxx
@@ -13,6 +13,7 @@
 ////////////////////////////////////////////////////////////////////
 
 #include "p3dMainObject.h"
+#include "p3dPythonObject.h"
 #include "p3dInstance.h"
 #include "p3dSession.h"
 #include "p3dStringObject.h"