diff --git a/direct/src/ffi/FFIOverload.py b/direct/src/ffi/FFIOverload.py
index fb2b7bdb4c..102f1231bf 100644
--- a/direct/src/ffi/FFIOverload.py
+++ b/direct/src/ffi/FFIOverload.py
@@ -79,7 +79,7 @@ def getTypeName(classTypeDesc, typeDesc):
             return 'types.NoneType'
 
         else:
-            FFIConstants.notify.error("Unknown atomicType: " + typeDesc.atomicType)
+            FFIConstants.notify.error("Unknown atomicType: %s" % (typeDesc.atomicType))
         
     # If the type is an enum, we really want to treat it like an int
     # To handle this, the type will have __enum__ in the name