diff --git a/libtaskmanager/taskgroupingproxymodel.cpp b/libtaskmanager/taskgroupingproxymodel.cpp
index 3c13b0c1e..67a50dfe2 100644
--- a/libtaskmanager/taskgroupingproxymodel.cpp
+++ b/libtaskmanager/taskgroupingproxymodel.cpp
@@ -599,6 +599,15 @@ int TaskGroupingProxyModel::rowCount(const QModelIndex &parent) const
     return d->rowMap.count();
 }
 
+bool TaskGroupingProxyModel::hasChildren(const QModelIndex &parent) const
+{
+    if ((parent.model() && parent.model() != this) || !sourceModel()) {
+        return false;
+    }
+
+    return rowCount(parent);
+}
+
 int TaskGroupingProxyModel::columnCount(const QModelIndex &parent) const
 {
     Q_UNUSED(parent)
diff --git a/libtaskmanager/taskgroupingproxymodel.h b/libtaskmanager/taskgroupingproxymodel.h
index 89e6bebfd..73e5b150d 100644
--- a/libtaskmanager/taskgroupingproxymodel.h
+++ b/libtaskmanager/taskgroupingproxymodel.h
@@ -62,6 +62,7 @@ public:
     QModelIndex mapToSource(const QModelIndex &proxyIndex) const override;
 
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+    bool hasChildren(const QModelIndex &parent = QModelIndex()) const override;
     int columnCount(const QModelIndex &parent = QModelIndex()) const override;
 
     QVariant data(const QModelIndex &proxyIndex, int role) const override;