diff --git a/dtool/src/cppparser/cppClosureType.cxx b/dtool/src/cppparser/cppClosureType.cxx
index cf8ec31143..30197057a6 100755
--- a/dtool/src/cppparser/cppClosureType.cxx
+++ b/dtool/src/cppparser/cppClosureType.cxx
@@ -12,6 +12,7 @@
  */
 
 #include "cppClosureType.h"
+#include "cppParameterList.h"
 #include "cppExpression.h"
 
 /**