diff --git a/src/main_wayland.cpp b/src/main_wayland.cpp
index 9ea4c9b84..9e8be17ad 100644
--- a/src/main_wayland.cpp
+++ b/src/main_wayland.cpp
@@ -500,6 +500,27 @@ int main(int argc, char * argv[])
     // 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");
 
+#if !defined(QT_NO_DEBUG)
+    QStringList newLibPaths(a.applicationDirPath());
+    const QStringList oldLibPaths = QCoreApplication::libraryPaths();
+    if (newLibPaths.contains("/usr/local/bin")) {
+        // when do “make install”, we need add plugins directory before normal qt plugins directory.
+        // we can get arch lib directory name from qt plugins directory and do a replace
+        // from "/usr/lib/x86_64-linux-gnu/qt5/plugins" to "/usr/local/lib/x86_64-linux-gnu/plugins"
+        // then kwin will load the right plugins.
+        QRegularExpression re("^/usr/lib/(.*)/qt.*$");
+        QStringList plugins = oldLibPaths.filter(QRegularExpression("^/usr/lib/"))
+                                         .replaceInStrings(re, "/usr/local/lib/\\1/plugins");
+        newLibPaths.append(plugins);
+    }
+    newLibPaths.append(oldLibPaths);
+    QCoreApplication::setLibraryPaths(newLibPaths);
+    qDebug() << "debug mode:";
+    qDebug() << "   set application dir path to be the first of libraryPaths,";
+    qDebug() << "   so we can be happy to debug kwin plugins.";
+    qDebug() << "   libraryPaths:" << newLibPaths;
+#endif
+
     KWin::Application::createAboutData();
     KQuickAddons::QtQuickSettings::init();
 
diff --git a/src/main_x11.cpp b/src/main_x11.cpp
index 4171a861a..f92345164 100644
--- a/src/main_x11.cpp
+++ b/src/main_x11.cpp
@@ -537,6 +537,27 @@ int main(int argc, char * argv[])
     KWin::ApplicationX11 a(argc, argv);
     a.setupTranslator();
 
+#if !defined(QT_NO_DEBUG)
+    QStringList newLibPaths(a.applicationDirPath());
+    const QStringList oldLibPaths = QCoreApplication::libraryPaths();
+    if (newLibPaths.contains("/usr/local/bin")) {
+        // when do “make install”, we need add plugins directory before normal qt plugins directory.
+        // we can get arch lib directory name from qt plugins directory and do a replace
+        // from "/usr/lib/x86_64-linux-gnu/qt5/plugins" to "/usr/local/lib/x86_64-linux-gnu/plugins"
+        // then kwin will load the right plugins.
+        QRegularExpression re("^/usr/lib/(.*)/qt.*$");
+        QStringList plugins = oldLibPaths.filter(QRegularExpression("^/usr/lib/"))
+                                         .replaceInStrings(re, "/usr/local/lib/\\1/plugins");
+        newLibPaths.append(plugins);
+    }
+    newLibPaths.append(oldLibPaths);
+    QCoreApplication::setLibraryPaths(newLibPaths);
+    qDebug() << "debug mode:";
+    qDebug() << "   set application dir path to be the first of libraryPaths,";
+    qDebug() << "   so we can be happy to debug kwin plugins.";
+    qDebug() << "   libraryPaths:" << newLibPaths;
+#endif
+
     KWin::Application::createAboutData();
     KQuickAddons::QtQuickSettings::init();