diff --git a/pilot/server/webserver.py b/pilot/server/webserver.py
index a76cf3400..e3d7a6dbb 100644
--- a/pilot/server/webserver.py
+++ b/pilot/server/webserver.py
@@ -266,7 +266,7 @@ def http_bot(state, mode, sql_mode, db_selector, temperature, max_new_tokens, re
             result = prompt_template.format(context="\n".join(context), question=query)
             state.messages[-2][1] = result
             prompt = state.get_prompt()
-            print("new prompt length:" + len(prompt))
+            print("new prompt length:" + str(len(prompt)))
 
         state.messages[-2][1] = query
         skip_echo_len = len(prompt.replace("</s>", " ")) + 1