diff --git a/autotests/integration/effects/translucency_test.cpp b/autotests/integration/effects/translucency_test.cpp
--- a/autotests/integration/effects/translucency_test.cpp
+++ b/autotests/integration/effects/translucency_test.cpp
@@ -71,11 +71,10 @@
         plugins.writeEntry(name + QStringLiteral("Enabled"), false);
     }
     config->group("Outline").writeEntry(QStringLiteral("QmlPath"), QString("/does/not/exist.qml"));
+    config->group("Effect-kwin4_effect_translucency").writeEntry(QStringLiteral("Dialogs"), 90);
 
     config->sync();
     kwinApp()->setConfig(config);
-    // TODO: make effects use KWin's config directly
-    KSharedConfig::openConfig(QStringLiteral(KWIN_CONFIG), KConfig::NoGlobals)->group("Effect-kwin4_effect_translucency").writeEntry(QStringLiteral("Dialogs"), 90);
 
     qputenv("KWIN_EFFECTS_FORCE_ANIMATIONS", "1");
     kwinApp()->start();
diff --git a/scripting/scriptedeffect.cpp b/scripting/scriptedeffect.cpp
--- a/scripting/scriptedeffect.cpp
+++ b/scripting/scriptedeffect.cpp
@@ -23,6 +23,7 @@
 #include "scriptingutils.h"
 #include "workspace_wrapper.h"
 #include "../screenedge.h"
+#include "../main.h"
 #include "scripting_logging.h"
 // KDE
 #include <KConfigGroup>
@@ -482,7 +483,7 @@
     // does the effect contain an KConfigXT file?
     const QString kconfigXTFile = QStandardPaths::locate(QStandardPaths::GenericDataLocation, QLatin1String(KWIN_NAME "/effects/") + m_effectName + QLatin1String("/contents/config/main.xml"));
     if (!kconfigXTFile.isNull()) {
-        KConfigGroup cg = effects->effectConfig(m_effectName);
+        KConfigGroup cg = kwinApp()->config()->group(QStringLiteral("Effect-%1").arg(m_effectName));
         QFile xmlFile(kconfigXTFile);
         m_config = new KConfigLoader(cg, &xmlFile, this);
         m_config->load();