diff --git a/autotests/kdeplatformtheme_unittest.cpp b/autotests/kdeplatformtheme_unittest.cpp
--- a/autotests/kdeplatformtheme_unittest.cpp
+++ b/autotests/kdeplatformtheme_unittest.cpp
@@ -46,6 +46,7 @@
 #include <QTimer>
 #include <QX11Info>
 
+#include <KIconTheme>
 #include <kiconloader.h>
 #include <KWindowInfo>
 
@@ -203,6 +204,13 @@
         QCOMPARE(engine->key(), QStringLiteral("KIconEngine"));
     }
 
+    void testPlatformIconEngineTheme()
+    {
+        // The current theme should be what we defined.
+        KdePlatformTheme().createIconEngine(QStringLiteral("test-icon"));
+        QCOMPARE(KIconLoader::global()->theme()->current(), QStringLiteral("non-existent-icon-theme"));
+    }
+
     void testPlatformIconChanges()
     {
         QString configPath = QStandardPaths::writableLocation(QStandardPaths::GenericConfigLocation);