diff --git a/airflow/providers/amazon/aws/sensors/s3.py b/airflow/providers/amazon/aws/sensors/s3.py
index 884318bfda2..b31b9cdceba 100644
--- a/airflow/providers/amazon/aws/sensors/s3.py
+++ b/airflow/providers/amazon/aws/sensors/s3.py
@@ -179,8 +179,9 @@ def poke(self, context: 'Context'):
         s3_objects = self.get_files(s3_hook=self.get_hook())
         if not s3_objects:
             return False
-        check_fn = self.check_fn if self.check_fn_user is None else self.check_fn_user
-        return check_fn(s3_objects)
+        if self.check_fn_user is not None:
+            return self.check_fn_user(s3_objects)
+        return self.check_fn(s3_objects)
 
     def get_files(self, s3_hook: S3Hook, delimiter: Optional[str] = '/') -> List:
         """Gets a list of files in the bucket"""