diff --git a/compiler/coreSyn/CoreUnfold.lhs b/compiler/coreSyn/CoreUnfold.lhs
index 6a737161d32d6d3935f57d4e7cb474fab0e8beba..782264fb6de950f0425c8683f0fb979c3b3b1055 100644
--- a/compiler/coreSyn/CoreUnfold.lhs
+++ b/compiler/coreSyn/CoreUnfold.lhs
@@ -400,7 +400,7 @@ sizeExpr bOMB_OUT_SIZE top_args expr
 
 	  alts_size tot_size _ = tot_size
 
-    size_up (Case e b _ alts) = size_up e  `addSizeNSD`
+    size_up (Case e _ _ alts) = size_up e  `addSizeNSD`
                                 foldr (addAltSize . size_up_alt) case_size alts
       where
           case_size