diff --git a/qubes/tests/integ/basic.py b/qubes/tests/integ/basic.py
index ed8e37cc6..da63edadd 100644
--- a/qubes/tests/integ/basic.py
+++ b/qubes/tests/integ/basic.py
@@ -472,7 +472,10 @@ def setUp(self):
         super(TC_30_Gui_daemon, self).setUp()
         self.init_default_template()
 
-    async def _test_clipboard(self, test_string):
+    async def _test_clipboard(self, test_string,
+                              set_features=None,
+                              expect_content=None,
+                              expect_source_name=None):
         testvm1 = self.app.add_new_vm(
             qubes.vm.appvm.AppVM,
             name=self.make_vm_name('vm1'), label='red')
@@ -483,6 +486,9 @@ async def _test_clipboard(self, test_string):
         await testvm2.create_on_disk()
         self.app.save()
 
+        for feature, value in (set_features or {}).items():
+            testvm1.features[feature] = value
+
         await asyncio.gather(
             testvm1.start(),
             testvm2.start())
@@ -514,18 +520,23 @@ async def _test_clipboard(self, test_string):
 
         clipboard_content = \
             open('/var/run/qubes/qubes-clipboard.bin', 'r').read().strip()
+
+        if expect_content is not None:
+            test_string = expect_content
         self.assertEqual(clipboard_content, test_string,
                           "Clipboard copy operation failed - content")
+        if expect_source_name is None:
+            expect_source_name = testvm1.name
         clipboard_source = \
             open('/var/run/qubes/qubes-clipboard.bin.source',
                  'r').read().strip()
-        self.assertEqual(clipboard_source, testvm1.name,
+        self.assertEqual(clipboard_source, expect_source_name,
                           "Clipboard copy operation failed - owner")
 
         # Then paste it to the other window
         window_title = 'user@{}'.format(testvm2.name)
         p = await testvm2.run(
-            'zenity --entry --title={} > /tmp/test.txt'.format(window_title))
+            'zenity --text-info --editable --title={} > /tmp/test.txt'.format(window_title))
         await self.wait_for_window_coro(window_title)
 
         subprocess.check_call(['xdotool', 'key', '--delay', '100',
@@ -553,6 +564,38 @@ def test_000_clipboard(self):
         test_string = "test123"
         self.loop.run_until_complete(self._test_clipboard(test_string))
 
+    @unittest.skipUnless(
+        spawn.find_executable('xdotool'),
+                         "xdotool not installed")
+    def test_001_clipboard_64k(self):
+        test_string = "test123abc" * 6400
+        self.loop.run_until_complete(self._test_clipboard(test_string))
+
+    @unittest.skipUnless(
+        spawn.find_executable('xdotool'),
+                         "xdotool not installed")
+    def test_002_clipboard_200k_truncated(self):
+        test_string = "test123abc" * 20000
+        self.loop.run_until_complete(self._test_clipboard(test_string,
+            expect_content="", expect_source_name=""))
+
+    @unittest.skipUnless(
+        spawn.find_executable('xdotool'),
+                         "xdotool not installed")
+    def test_002_clipboard_200k(self):
+        test_string = "test123abc" * 20000
+        self.loop.run_until_complete(self._test_clipboard(test_string,
+            set_features={"gui-max-clipboard-size": 200_000}))
+
+    @unittest.skipUnless(
+        spawn.find_executable('xdotool'),
+                         "xdotool not installed")
+    def test_002_clipboard_300k(self):
+        test_string = "test123abc" * 30000
+        self.loop.run_until_complete(self._test_clipboard(test_string,
+            expect_content="Qube clipboard size over 256KiB and X11 INCR "
+                           "protocol support is not implemented!"))
+
 
 class TC_05_StandaloneVMMixin(object):
     def setUp(self):