diff --git a/src/diffusers/configuration_utils.py b/src/diffusers/configuration_utils.py
index e47e9d902d0b..8f4a1958975d 100644
--- a/src/diffusers/configuration_utils.py
+++ b/src/diffusers/configuration_utils.py
@@ -450,8 +450,8 @@ def load_config(
         return outputs
 
     @staticmethod
-    def _get_init_keys(cls):
-        return set(dict(inspect.signature(cls.__init__).parameters).keys())
+    def _get_init_keys(input_class):
+        return set(dict(inspect.signature(input_class.__init__).parameters).keys())
 
     @classmethod
     def extract_init_dict(cls, config_dict, **kwargs):