diff --git a/kcmkwin/kwincompositing/model.cpp b/kcmkwin/kwincompositing/model.cpp
index 6e6f9fc337..8c848adfae 100644
--- a/kcmkwin/kwincompositing/model.cpp
+++ b/kcmkwin/kwincompositing/model.cpp
@@ -80,6 +80,7 @@ QModelIndex EffectModel::parent(const QModelIndex &child) const {
 }
 
 int EffectModel::columnCount(const QModelIndex &parent) const {
+    Q_UNUSED(parent)
     return 1;
 }