diff --git a/library/init/tactic.lean b/library/init/tactic.lean
index 3ec343a0eb..83047789ea 100644
--- a/library/init/tactic.lean
+++ b/library/init/tactic.lean
@@ -21,7 +21,7 @@ namespace tactic
 -- a term of type 'tactic' into a tactic that sythesizes a term
 definition and_then    (t1 t2 : tactic) : tactic := builtin
 definition or_else     (t1 t2 : tactic) : tactic := builtin
-definition append      (t1 t2 : tactic) : tactic := builtin
+definition par         (t1 t2 : tactic) : tactic := builtin
 definition fixpoint    (f : tactic → tactic) : tactic := builtin
 definition repeat      (t : tactic) : tactic := builtin
 definition at_most     (t : tactic) (k : num)  : tactic := builtin