diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index d0d27b5..7c3cd94 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -108,8 +108,27 @@
 func Test_win_execute_closing_curwin()
   split
   let winid = popup_create('some text', {})
-  call win_execute(winid, winnr() .. "close")
-  call assert_equal(1, winnr())
+  call assert_fails('call win_execute(winid, winnr() .. "close")', 'E994')
+  popupclear
+endfunc
+
+func Test_win_execute_not_allowed()
+  let winid = popup_create('some text', {})
+  call assert_fails('call win_execute(winid, "split")', 'E994:')
+  call assert_fails('call win_execute(winid, "vsplit")', 'E994:')
+  call assert_fails('call win_execute(winid, "close")', 'E994:')
+  call assert_fails('call win_execute(winid, "bdelete")', 'E994:')
+  call assert_fails('call win_execute(winid, "tabnew")', 'E994:')
+  call assert_fails('call win_execute(winid, "tabnext")', 'E994:')
+  call assert_fails('call win_execute(winid, "next")', 'E994:')
+  call assert_fails('call win_execute(winid, "rewind")', 'E994:')
+  call assert_fails('call win_execute(winid, "buf")', 'E994:')
+  call assert_fails('call win_execute(winid, "edit")', 'E994:')
+  call assert_fails('call win_execute(winid, "enew")', 'E994:')
+  call assert_fails('call win_execute(winid, "wincmd x")', 'E994:')
+  call assert_fails('call win_execute(winid, "wincmd w")', 'E994:')
+  call assert_fails('call win_execute(winid, "wincmd t")', 'E994:')
+  call assert_fails('call win_execute(winid, "wincmd b")', 'E994:')
   popupclear
 endfunc