diff --git a/src/plugins/projectexplorer/task.h b/src/plugins/projectexplorer/task.h
index a6d4451236eb8fa5bfce7502b45517024bd7cf2a..c86811647c26049a184ea7ea33bb159f5ee97ecb 100644
--- a/src/plugins/projectexplorer/task.h
+++ b/src/plugins/projectexplorer/task.h
@@ -39,7 +39,9 @@
 namespace ProjectExplorer {
 
 // Build issue (warning or error).
-struct PROJECTEXPLORER_EXPORT Task {
+class PROJECTEXPLORER_EXPORT Task
+{
+public:
     enum TaskType {
         Unknown,
         Error,
diff --git a/src/plugins/projectexplorer/taskwindow.cpp b/src/plugins/projectexplorer/taskwindow.cpp
index 9f08ed672153082dd942799e3a3c91f5b3fb870e..debdb12263a03e1bd9d9fb78a45230837cdadc5a 100644
--- a/src/plugins/projectexplorer/taskwindow.cpp
+++ b/src/plugins/projectexplorer/taskwindow.cpp
@@ -478,7 +478,9 @@ bool TaskFilterModel::filterAcceptsRow(int sourceRow, const QModelIndex &sourceP
 // TaskWindow
 /////
 
-struct TaskWindowPrivate {
+class TaskWindowPrivate
+{
+public:
     Internal::TaskModel *m_model;
     Internal::TaskFilterModel *m_filter;
     Internal::TaskView *m_listview;
diff --git a/src/plugins/projectexplorer/taskwindow.h b/src/plugins/projectexplorer/taskwindow.h
index 9ba2ad9451f71a11c41a42cbed89d2779cd65dcb..8152d93b4f900096f081f7844354c10fdd1898c1 100644
--- a/src/plugins/projectexplorer/taskwindow.h
+++ b/src/plugins/projectexplorer/taskwindow.h
@@ -42,10 +42,8 @@ class QModelIndex;
 QT_END_NAMESPACE
 
 namespace ProjectExplorer {
-struct Task;
-struct TaskWindowPrivate;
-
-struct TaskWindowPrivate;
+class Task;
+class TaskWindowPrivate;
 
 // Show build issues (warnings or errors) and open the editor on click.
 class PROJECTEXPLORER_EXPORT TaskWindow : public Core::IOutputPane