diff -Naur a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt	2023-11-05 17:52:24.000000000 +0600
+++ b/CMakeLists.txt	2023-11-07 10:19:45.144114340 +0600
@@ -16,7 +16,7 @@
 option(UPDATE_TRANSLATIONS "Update source translation translations/*.ts files" OFF)
 
 set(LXQTBT_MINIMUM_VERSION "0.13.0")
-set(KF5_MINIMUM_VERSION "5.101.0")
+set(KF5_MINIMUM_VERSION "5.96.0")
 set(LXQT_MINIMUM_VERSION "1.4.0")
 set(QT_MINIMUM_VERSION "5.15.0")
 
diff -Naur a/src/idlenesswatcher.cpp b/src/idlenesswatcher.cpp
--- a/src/idlenesswatcher.cpp	2023-11-05 17:52:24.000000000 +0600
+++ b/src/idlenesswatcher.cpp	2023-11-07 10:20:39.853753021 +0600
@@ -30,7 +30,6 @@
 #include <Solid/Device>
 #include <Solid/Battery>
 #include <KWindowSystem/KWindowSystem>
-#include <KWindowSystem/KX11Extras>
 #include <KWindowSystem/KWindowInfo>
 #include <QDebug>
 #include <LXQt/lxqtnotification.h>
@@ -162,7 +161,7 @@
 
     // check if disable Idleness when fullscreen is enabled
     if (mPSettings.isDisableIdlenessWhenFullscreenEnabled()) {
-        WId w = KX11Extras::activeWindow();
+        WId w = KWindowSystem::activeWindow();
         KWindowInfo info(w, NET::WMState);
         if (info.hasState(NET::FullScreen)) {
             QTimer::singleShot(0, this, [] {