diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 15ec7d8..a0f3ffd 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -854,6 +854,11 @@
   call feedkeys(":disas s:WeirdF\<C-A>\<C-B>\"\<CR>", 'xt')
   call assert_match('"disas <SNR>\d\+_WeirdFunc', @:)
 
+  call feedkeys(":disas \<S-Tab>\<C-B>\"\<CR>", 'xt')
+  call assert_match('"disas <SNR>\d\+_', @:)
+  call feedkeys(":disas debug \<S-Tab>\<C-B>\"\<CR>", 'xt')
+  call assert_match('"disas debug <SNR>\d\+_', @:)
+
   " completion for the :match command
   call feedkeys(":match Search /pat/\<C-A>\<C-B>\"\<CR>", 'xt')
   call assert_equal("\"match Search /pat/\<C-A>", @:)