diff --git a/panda/src/putil/bamReaderParam.h b/panda/src/putil/bamReaderParam.h
index 7a6ad2925f..00d1d2c496 100644
--- a/panda/src/putil/bamReaderParam.h
+++ b/panda/src/putil/bamReaderParam.h
@@ -53,7 +53,7 @@ public:
     return _type_handle;
   }
   static void init_type() {
-    TypedReferenceCount::init_type();
+    FactoryParam::init_type();
     register_type(_type_handle, "BamReaderParam",
                   FactoryParam::get_class_type());
   }
diff --git a/panda/src/putil/writableParam.h b/panda/src/putil/writableParam.h
index 9c1b53c7aa..a955c11c79 100644
--- a/panda/src/putil/writableParam.h
+++ b/panda/src/putil/writableParam.h
@@ -58,7 +58,7 @@ public:
     return _type_handle;
   }
   static void init_type() {
-    TypedReferenceCount::init_type();
+    FactoryParam::init_type();
     register_type(_type_handle, "WritableParam",
                   FactoryParam::get_class_type());
   }