diff --git a/tests/auto/network/access/qnetworkreply/BLACKLIST b/tests/auto/network/access/qnetworkreply/BLACKLIST
index 868406b520a..0da04b0a93f 100644
--- a/tests/auto/network/access/qnetworkreply/BLACKLIST
+++ b/tests/auto/network/access/qnetworkreply/BLACKLIST
@@ -7,6 +7,10 @@ windows-10 msvc-2015
 [authenticationCacheAfterCancel:https+socksauth]
 ubuntu-20.04
 
+# QTBUG-88417
+[authenticationCacheAfterCancel:https+proxyauth]
+ubuntu-20.04
+
 [backgroundRequestInterruption]
 opensuse-leap
 windows-10 msvc-2015