diff --git a/src/testdir/test_listdict.vim b/src/testdir/test_listdict.vim
index 4476e2b..7c707d4 100644
--- a/src/testdir/test_listdict.vim
+++ b/src/testdir/test_listdict.vim
@@ -1045,7 +1045,7 @@
 
   call assert_fails("call reduce({}, { acc, val -> acc + val }, 1)", 'E1098:')
   call assert_fails("call reduce(0, { acc, val -> acc + val }, 1)", 'E1098:')
-  call assert_fails("call reduce([1, 2], 'Xdoes_not_exist')", 'E117:')
+  call assert_fails("call reduce([1, 2], 'Xdoes_not_exist')", 'E121:')
   call assert_fails("echo reduce(0z01, { acc, val -> 2 * acc + val }, '')", 'E1210:')
 
   call assert_fails("vim9 reduce(0, (acc, val) => (acc .. val), '')", 'E1252:')