diff --git a/autotests/integration/effects/slidingpopups_test.cpp b/autotests/integration/effects/slidingpopups_test.cpp
--- a/autotests/integration/effects/slidingpopups_test.cpp
+++ b/autotests/integration/effects/slidingpopups_test.cpp
@@ -60,6 +60,7 @@
 
 void SlidingPopupsTest::initTestCase()
 {
+    qputenv("XDG_DATA_DIRS", QCoreApplication::applicationDirPath().toUtf8());
     qRegisterMetaType<KWin::ShellClient*>();
     qRegisterMetaType<KWin::AbstractClient*>();
     qRegisterMetaType<KWin::Deleted*>();