diff --git a/src/testdir/test_gui.vim b/src/testdir/test_gui.vim
index f2d82e4..0f2a962 100644
--- a/src/testdir/test_gui.vim
+++ b/src/testdir/test_gui.vim
@@ -643,6 +643,15 @@
       call assert_equal('aegi', &guioptions)
     endif
 
+    if has('gui_gtk3')
+      set guioptions+=d
+      exec 'sleep' . duration
+      call assert_equal('aegid', &guioptions)
+      set guioptions-=d
+      exec 'sleep' . duration
+      call assert_equal('aegi', &guioptions)
+    endif
+
     " Restore GUI ornaments to the default state.
     set guioptions+=m
     exec 'sleep' . duration