diff --git a/tests/auto/qmenu/qmenu.pro b/tests/auto/qmenu/qmenu.pro
index 3a32920b140..63451a11b6e 100644
--- a/tests/auto/qmenu/qmenu.pro
+++ b/tests/auto/qmenu/qmenu.pro
@@ -1,2 +1,4 @@
 load(qttest_p4)
 SOURCES  += tst_qmenu.cpp
+
+qpa:contains(QT_CONFIG,xcb):CONFIG+=insignificant_test  # QTBUG-21100, unstably fails