diff --git a/kcmkwin/kwintabbox/main.cpp b/kcmkwin/kwintabbox/main.cpp
index afebf83bbe..ba03aa60af 100644
--- a/kcmkwin/kwintabbox/main.cpp
+++ b/kcmkwin/kwintabbox/main.cpp
@@ -364,7 +364,7 @@ void KWinTabBoxConfig::defaults()
         CONFIGURE(showDesktop, ShowDesktop, ==, ShowDesktopClient);
 #undef CONFIGURE
         // effects
-        ui[i]->effectCombo->setCurrentIndex(ui[i]->effectCombo->findData("thumbnails"));
+        ui[i]->effectCombo->setCurrentIndex(ui[i]->effectCombo->findData("sidebar"));
     }
 
     QString action;
diff --git a/tabbox/tabboxconfig.h b/tabbox/tabboxconfig.h
index d6c077173b..f953102986 100644
--- a/tabbox/tabboxconfig.h
+++ b/tabbox/tabboxconfig.h
@@ -314,7 +314,7 @@ public:
         return true;
     }
     static QString defaultLayoutName() {
-        return QStringLiteral("thumbnails");
+        return QStringLiteral("sidebar");
     }
 private:
     TabBoxConfigPrivate* d;