diff --git a/backend/config.py b/backend/config.py
index 32e64347e..30a23f29e 100644
--- a/backend/config.py
+++ b/backend/config.py
@@ -680,9 +680,11 @@ Question:
 SEARCH_QUERY_PROMPT_LENGTH_THRESHOLD = PersistentConfig(
     "SEARCH_QUERY_PROMPT_LENGTH_THRESHOLD",
     "task.search.prompt_length_threshold",
-    os.environ.get(
-        "SEARCH_QUERY_PROMPT_LENGTH_THRESHOLD",
-        100,
+    int(
+        os.environ.get(
+            "SEARCH_QUERY_PROMPT_LENGTH_THRESHOLD",
+            100,
+        )
     ),
 )