diff --git a/ghc/compiler/simplCore/SimplCore.lhs b/ghc/compiler/simplCore/SimplCore.lhs
index be827a813c1a42ab5c23c2f071a83e6a385cd29b..f345c08325d42cc14ca176eda00eb36314fcd5e3 100644
--- a/ghc/compiler/simplCore/SimplCore.lhs
+++ b/ghc/compiler/simplCore/SimplCore.lhs
@@ -305,6 +305,8 @@ tidyAlt env (con, vs, rhs)   = (con, vs', tidyExpr env' rhs)
 			       (env', vs') = mapAccumL tidyNestedBndr env vs
 
 tidyNote env (Coerce t1 t2)  = Coerce (tidyType env t1) (tidyType env t2)
+
+tidyNote env note            = note
 \end{code}
 
 \begin{code}