diff --git a/direct/src/p3d/thirdparty.pdef b/direct/src/p3d/thirdparty.pdef
index 175e40bed2..2ad164a372 100644
--- a/direct/src/p3d/thirdparty.pdef
+++ b/direct/src/p3d/thirdparty.pdef
@@ -13,6 +13,8 @@
 
 # Also see panda3d.pdef.
 
+import sys
+
 class wx(package):
     config(display_name = "wxPython GUI Toolkit")
     #config(gui_app = True)