diff --git a/theories/tactics.v b/theories/tactics.v
index 5c8199a5bfaf52a098996c1952ad0a48687490a4..8391f697b471647c55d9d64386792250cc824041 100644
--- a/theories/tactics.v
+++ b/theories/tactics.v
@@ -66,7 +66,7 @@ Ltac done :=
     | discriminate
     | contradiction
     | split
-    | match goal with H : ¬_ |- _ => case H; clear H; done end
+    | match goal with H : ¬_ |- _ => case H; clear H; fast_done end
     ]
   ].
 Tactic Notation "by" tactic(tac) :=