diff --git a/generator/stdlib_ml/stdlib.mli b/generator/stdlib_ml/stdlib.mli
index 1f33fcef23bd90bfe6b2a1ef849edf1d1815a83b..f151742938d1e4e9b060c0b3ff40613ebd1c16c2 100644
--- a/generator/stdlib_ml/stdlib.mli
+++ b/generator/stdlib_ml/stdlib.mli
@@ -102,6 +102,7 @@ module String : sig
   val concat : string -> string list -> string
   val iter : (char -> unit) -> string -> unit
   val make : int -> char -> string
+  val get : string -> int -> char
 end
 
 (* Coq outputs exceptions in the place of arbitrary *)