diff --git a/src/testdir/test_diffmode.vim b/src/testdir/test_diffmode.vim
index 6f4eaaf..9dfe2fe 100644
--- a/src/testdir/test_diffmode.vim
+++ b/src/testdir/test_diffmode.vim
@@ -989,3 +989,22 @@
   diffoff!
   enew!
 endfunc
+
+func Test_diff_maintains_change_mark()
+  enew!
+  call setline(1, ['a', 'b', 'c', 'd'])
+  diffthis
+  new
+  call setline(1, ['a', 'b', 'c', 'e'])
+  " Set '[ and '] marks
+  2,3yank
+  call assert_equal([2, 3], [line("'["), line("']")])
+  " Verify they aren't affected by the implicit diff
+  diffthis
+  call assert_equal([2, 3], [line("'["), line("']")])
+  " Verify they aren't affected by an explicit diff
+  diffupdate
+  call assert_equal([2, 3], [line("'["), line("']")])
+  bwipe!
+  bwipe!
+endfunc