diff --git a/src/main_x11.cpp b/src/main_x11.cpp
index 74b162cbec..466ff7b6d2 100644
--- a/src/main_x11.cpp
+++ b/src/main_x11.cpp
@@ -376,9 +376,13 @@ int main(int argc, char *argv[])
     // enforce xcb plugin, unfortunately command line switch has precedence
     setenv("QT_QPA_PLATFORM", "xcb", true);
 
+    // disable highdpi scaling
+    setenv("QT_ENABLE_HIGHDPI_SCALING", "0", true);
+
     qunsetenv("QT_DEVICE_PIXEL_RATIO");
     qunsetenv("QT_SCALE_FACTOR");
-    QCoreApplication::setAttribute(Qt::AA_DisableHighDpiScaling);
+    qunsetenv("QT_SCREEN_SCALE_FACTORS");
+
     // KSMServer talks to us directly on DBus.
     QCoreApplication::setAttribute(Qt::AA_DisableSessionManager);
     // For sharing thumbnails between our scene graph and qtquick.
@@ -393,8 +397,10 @@ int main(int argc, char *argv[])
 
     KWin::ApplicationX11 a(argc, argv);
     a.setupTranslator();
+
     // reset QT_QPA_PLATFORM so we don't propagate it to our children (e.g. apps launched from the overview effect)
     qunsetenv("QT_QPA_PLATFORM");
+    qunsetenv("QT_ENABLE_HIGHDPI_SCALING");
 
     KSignalHandler::self()->watchSignal(SIGTERM);
     KSignalHandler::self()->watchSignal(SIGINT);