diff --git a/examples/hashtbl_impl.mlw b/examples/hashtbl_impl.mlw
index 11d73f76c95a4c4c0557f79f66168c26bb93aa39..35e807f956f6d0fa1806c0e5ced2ab3a3a86faa1 100644
--- a/examples/hashtbl_impl.mlw
+++ b/examples/hashtbl_impl.mlw
@@ -1,3 +1,9 @@
+
+(* Hash table implementation
+
+   Jean-Christophe Filliâtre (CNRS)
+   Andrei Paskevich (Univ Paris Sud) *)
+
 module HashtblImpl
 
   use import int.Int