diff --git a/refl.hpp b/refl.hpp
index 7098e07..e3040b3 100644
--- a/refl.hpp
+++ b/refl.hpp
@@ -4136,7 +4136,7 @@ namespace refl::detail
 /********************************/
 
 #define REFL_DETAIL_PRIMITIVE(TypeName) \
-    REFL_TYPE(TypeName) \
+    REFL_TYPE(TypeName,) \
     REFL_END
 
     // Char types.