diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 6928cda..724fda0 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -2244,6 +2244,11 @@
 
   call assert_fails("call input('F:', '', 'invalid')", 'E180:')
   call assert_fails("call input('F:', '', [])", 'E730:')
+
+  " Test for using 'command' as the completion function
+  call feedkeys(":let c = input('Command? ', '', 'command')\<CR>"
+        \ .. "echo bufnam\<C-A>\<CR>", 'xt')
+  call assert_equal('echo bufname(', c)
 endfunc
 
 " Test for the inputdialog() function