diff --git a/shell/screenpool.h b/shell/screenpool.h
--- a/shell/screenpool.h
+++ b/shell/screenpool.h
@@ -65,6 +65,7 @@
     QHash<QString, int> m_idForConnector;
 
     QTimer m_configSaveTimer;
+    int m_xrandrExtensionOffset;
 };
 
 #endif // SCREENPOOL_H
diff --git a/shell/screenpool.cpp b/shell/screenpool.cpp
--- a/shell/screenpool.cpp
+++ b/shell/screenpool.cpp
@@ -40,6 +40,9 @@
     connect(&m_configSaveTimer, &QTimer::timeout, this, [this](){
         m_configGroup.sync();
     });
+
+    const xcb_query_extension_reply_t* reply = xcb_get_extension_data(QX11Info::connection(), &xcb_randr_id);
+    m_xrandrExtensionOffset = reply->first_event;
 }
 
 void ScreenPool::load()
@@ -185,9 +188,8 @@
 
     const auto responseType = XCB_EVENT_RESPONSE_TYPE(ev);
 
-    const xcb_query_extension_reply_t* reply = xcb_get_extension_data(QX11Info::connection(), &xcb_randr_id);
 
-    if (responseType == reply->first_event + XCB_RANDR_SCREEN_CHANGE_NOTIFY) {
+    if (responseType == m_xrandrExtensionOffset + XCB_RANDR_SCREEN_CHANGE_NOTIFY) {
         if (qGuiApp->primaryScreen()->name() != primaryConnector()) {
             //new screen?
             if (id(qGuiApp->primaryScreen()->name()) < 0) {