diff --git a/knowledge_storm/rm.py b/knowledge_storm/rm.py
index dfcee5ef..f03e1792 100644
--- a/knowledge_storm/rm.py
+++ b/knowledge_storm/rm.py
@@ -386,7 +386,7 @@ def serper_runner(self, query_params):
 
         if response == None:
             raise RuntimeError(
-                f"Error had occured while running the search process.\n Error is {response.reason}, had failed with status code {response.status_code}"
+                f"Error had occurred while running the search process.\n Error is {response.reason}, had failed with status code {response.status_code}"
             )
 
         return response.json()