diff --git a/src/documents/index.py b/src/documents/index.py
index 9a7505da3..34e0fd14b 100644
--- a/src/documents/index.py
+++ b/src/documents/index.py
@@ -207,7 +207,7 @@ class DelayedQuery:
             try:
                 field, supported_query_filters = self.param_map[param]
             except KeyError:
-                logger.error("Unable to build a query filter for parameter %s", key)
+                logger.error(f"Unable to build a query filter for parameter {key}")
                 continue
 
             # We only support certain filters per parameter