diff --git a/libtaskmanager/abstracttasksmodel.h b/libtaskmanager/abstracttasksmodel.h
--- a/libtaskmanager/abstracttasksmodel.h
+++ b/libtaskmanager/abstracttasksmodel.h
@@ -59,6 +59,7 @@
         IsStartup,        /**< This is a startup task. */
         IsLauncher,       /**< This is a launcher task. */
         IsGroupParent,    /**< This is a parent item for a group of child tasks. */
+        ChildCount,       /**< The number of tasks in this group. */
         IsGroupable,      /**< Whether this task is being ignored by grouping or not. */
         IsActive,         /**< This is the currently active task. */
         IsClosable,       /**< requestClose (see below) available. */
diff --git a/libtaskmanager/taskgroupingproxymodel.cpp b/libtaskmanager/taskgroupingproxymodel.cpp
--- a/libtaskmanager/taskgroupingproxymodel.cpp
+++ b/libtaskmanager/taskgroupingproxymodel.cpp
@@ -419,13 +419,11 @@
 
         if (appsMatch(sourceIndex, groupRep)) {
             const QModelIndex parent = q->index(i, 0);
-            bool groupFormed = false;
 
             if (!silent) {
                 const int newIndex = rowMap.at(i).count();
 
                 if (newIndex == 1) {
-                    groupFormed = true;
                     q->beginInsertRows(parent, 0, 1);
                 } else {
                     q->beginInsertRows(parent, newIndex, newIndex);
@@ -437,14 +435,7 @@
             if (!silent) {
                 q->endInsertRows();
 
-                // If we turned a top-level item into a group parent, we need
-                // to let consumers know.
-                // TODO: It _might_ be worth optimizing this at some point by
-                // adding a roles constaint (e.g. IsGroupParent, MimeType, ...);
-                // see data().
-                if (groupFormed) {
-                    q->dataChanged(parent, parent);
-                }
+                q->dataChanged(parent, parent);
             }
 
             return true;
@@ -715,6 +706,8 @@
             return QVariant();
         } else if (role == AbstractTasksModel::IsGroupParent) {
             return true;
+        } else if (role == AbstractTasksModel::ChildCount) {
+            return rowCount(proxyIndex);
         } else if (role == AbstractTasksModel::IsActive) {
             return d->any(proxyIndex, AbstractTasksModel::IsActive);
         } else if (role == AbstractTasksModel::IsClosable) {