1 files changed, 11 insertions, 1 deletions
diff --git a/src/nvim/testdir/test55.in b/src/nvim/testdir/test55.in
index 7b6f684caa..9a55eac6f6 100644
--- a/src/nvim/testdir/test55.in
+++ b/src/nvim/testdir/test55.in
@@ -1,7 +1,6 @@
 Tests for List and Dictionary types.     vim: set ft=vim :
 
 STARTTEST
-:so small.vim
 :fun Test(...)
 :lang C
 :" Creating List directly with different types
@@ -442,6 +441,17 @@ let l = [0, 1, 2, 3]
 :unlockvar 1 b:
 :unlet! b:testvar
 :"
+:$put ='No :let += of locked list variable:'
+:let l = ['a', 'b', 3]
+:lockvar 1 l
+:try
+:  let l += ['x']
+:  $put ='did :let +='
+:catch
+:  $put =v:exception[:14]
+:endtry
+:$put =string(l)
+:"
 :unlet l
 :let l = [1, 2, 3, 4]
 :lockvar! l