diff --git a/utils.ml b/utils.ml
index b325db8..13d512a 100644
--- a/utils.ml
+++ b/utils.ml
@@ -60,12 +60,6 @@ let error fmt =
 let return = Lwt.return
 let fail = Lwt.fail
 
-(* Copy str to the start of buffer and fill the rest with zeros *)
-let set_fixed_string buffer str =
-  let len = String.length str in
-  Cstruct.blit_from_string str 0 buffer 0 len;
-  Cstruct.memset (Cstruct.shift buffer len) 0
-
 let or_fail msg = function
   | `Ok x -> return x
   | `Error _ -> fail (Failure msg)