diff -r fd73c5dbaad2 -r 018998c00003 src/HOL/Library/Multiset.thy
--- a/src/HOL/Library/Multiset.thy	Wed Sep 14 22:07:11 2016 +0200
+++ b/src/HOL/Library/Multiset.thy	Thu Sep 15 11:48:20 2016 +0200
@@ -3188,7 +3188,7 @@
 
 end
 
-lemma [code]: "sum_mset (mset xs) = listsum xs"
+lemma [code]: "sum_mset (mset xs) = sum_list xs"
   by (induct xs) simp_all
 
 lemma [code]: "prod_mset (mset xs) = fold times xs 1"