diff --git a/panda/src/parametrics/curveFitter.h b/panda/src/parametrics/curveFitter.h
index 6cc71ad632..d42a79504c 100644
--- a/panda/src/parametrics/curveFitter.h
+++ b/panda/src/parametrics/curveFitter.h
@@ -16,6 +16,7 @@
 #define CURVEFITTER_H
 
 #include <pandabase.h>
+#include "luse.h"
 #include <typedef.h>
 #include <vector>