diff --git a/benchs/run_benchs.ml b/benchs/run_benchs.ml
index c7cf8fe7..8e10fc0d 100644
--- a/benchs/run_benchs.ml
+++ b/benchs/run_benchs.ml
@@ -1217,7 +1217,7 @@ module Str = struct
         false
       else
         let sub = String.sub s 0 len_p in
-        String.equal prfx sub
+        CCString.equal prfx sub
 
     let bat_prefix ~pre:p str =
       let len = String.length p in