diff --git a/qutebrowser/browser/webengine/cookies.py b/qutebrowser/browser/webengine/cookies.py
index d9d11cd98..e5abc20ea 100644
--- a/qutebrowser/browser/webengine/cookies.py
+++ b/qutebrowser/browser/webengine/cookies.py
@@ -20,7 +20,7 @@
 """Filter for QtWebEngine cookies."""
 
 from qutebrowser.config import config
-from qutebrowser.utils import utils
+from qutebrowser.utils import utils, qtutils
 
 
 def _accept_cookie(request):
@@ -29,7 +29,13 @@ def _accept_cookie(request):
     if accept == 'all':
         return True
     elif accept in ['no-3rdparty', 'no-unknown-3rdparty']:
-        return not request.thirdParty
+        if qtutils.version_check('5.11.3', compiled=False):
+            third_party = request.thirdParty
+        else:
+            # WORKAROUND for https://bugreports.qt.io/browse/QTBUG-71393
+            third_party = (request.thirdParty and
+                           not request.firstPartyUrl.isEmpty())
+        return not third_party
     elif accept == 'never':
         return False
     else: