diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -52,6 +52,8 @@
     QUIET
 )
 
+find_package(LibKWorkspace ${PROJECT_VERSION} REQUIRED)
+
 # Disables automatic conversions from QString (or char *) to QUrl.
 add_definitions(-DQT_NO_URL_CAST_FROM_STRING)
 
diff --git a/kcmshell/CMakeLists.txt b/kcmshell/CMakeLists.txt
--- a/kcmshell/CMakeLists.txt
+++ b/kcmshell/CMakeLists.txt
@@ -11,6 +11,7 @@
    KF5::I18n
    KF5::WindowSystem
    KF5::Activities
+   PW::KWorkspace
 )
 
 install(TARGETS kdeinit_kcmshell5  ${KDE_INSTALL_TARGETS_DEFAULT_ARGS})
diff --git a/kcmshell/main.cpp b/kcmshell/main.cpp
--- a/kcmshell/main.cpp
+++ b/kcmshell/main.cpp
@@ -40,6 +40,8 @@
 #include <KStartupInfo>
 #include <KActivities/ResourceInstance>
 
+#include <kworkspace.h>
+
 #include <QIcon>
 #include <QCommandLineParser>
 #include <QCommandLineOption>
@@ -174,7 +176,13 @@
 
 extern "C" Q_DECL_EXPORT int kdemain(int _argc, char *_argv[])
 {
+    const bool qpaVariable = qEnvironmentVariableIsSet("QT_QPA_PLATFORM");
+    KWorkSpace::detectPlatform(argc, argv);
     KCMShell app(_argc, _argv);
+    if (!qpaVariable) {
+        // don't leak the env variable to processes we start
+        qunsetenv("QT_QPA_PLATFORM");
+    }
     KLocalizedString::setApplicationDomain("kcmshell5");
 
     app.setAttribute(Qt::AA_UseHighDpiPixmaps, true);