diff --git a/src/core/containers.ml b/src/core/containers.ml
index 62eb179d..1c527b6b 100644
--- a/src/core/containers.ml
+++ b/src/core/containers.ml
@@ -66,7 +66,7 @@ module Hashtbl = struct
   include (Hashtbl : module type of Hashtbl
     with type statistics = Hashtbl.statistics
     and module Make = Hashtbl.Make
-    and type ('a,'b) t := ('a,'b) Hashtbl.t
+    and type ('a,'b) t = ('a,'b) Hashtbl.t
   )
   (* still unable to include CCHashtbl itself, for the polymorphic functions *)
   module type S' = CCHashtbl.S