diff --git a/lib/model/classycat_schema_create.py b/lib/model/classycat_schema_create.py
index f04994d..9b66fc0 100644
--- a/lib/model/classycat_schema_create.py
+++ b/lib/model/classycat_schema_create.py
@@ -212,7 +212,7 @@ def process(self, message: Message) -> ClassyCatSchemaResponse:
 
 
     @classmethod
-    def verify_schema_parameters(schema_name, topics, examples, languages):
+    def verify_schema_parameters(cls, schema_name, topics, examples, languages):
 
         if not schema_name or not isinstance(schema_name, str) or len(schema_name) == 0:
             raise ValueError("schema_name is invalid. It must be a non-empty string")