diff --git a/src/plugins/help/openpagesswitcher.cpp b/src/plugins/help/openpagesswitcher.cpp
index c8fe4906674..7565f54c770 100644
--- a/src/plugins/help/openpagesswitcher.cpp
+++ b/src/plugins/help/openpagesswitcher.cpp
@@ -26,7 +26,6 @@
 #include "openpagesswitcher.h"
 
 #include "centralwidget.h"
-#include "openpagesmodel.h"
 #include "openpageswidget.h"
 
 #include <utils/hostosinfo.h>
@@ -41,7 +40,7 @@ using namespace Help::Internal;
 const int gWidth = 300;
 const int gHeight = 200;
 
-OpenPagesSwitcher::OpenPagesSwitcher(OpenPagesModel *model)
+OpenPagesSwitcher::OpenPagesSwitcher(QAbstractItemModel *model)
     : QFrame(nullptr, Qt::Popup)
     , m_openPagesModel(model)
 {
diff --git a/src/plugins/help/openpagesswitcher.h b/src/plugins/help/openpagesswitcher.h
index 1f3d7b24b14..da654d50a0a 100644
--- a/src/plugins/help/openpagesswitcher.h
+++ b/src/plugins/help/openpagesswitcher.h
@@ -27,12 +27,14 @@
 
 #include <QFrame>
 
-QT_FORWARD_DECLARE_CLASS(QModelIndex)
+QT_BEGIN_NAMESPACE
+class QAbstractItemModel;
+class QModelIndex;
+QT_END_NAMESPACE
 
 namespace Help {
     namespace Internal {
 
-class OpenPagesModel;
 class OpenPagesWidget;
 
 class OpenPagesSwitcher : public QFrame
@@ -40,7 +42,7 @@ class OpenPagesSwitcher : public QFrame
     Q_OBJECT
 
 public:
-    OpenPagesSwitcher(OpenPagesModel *model);
+    OpenPagesSwitcher(QAbstractItemModel *model);
     ~OpenPagesSwitcher() override;
 
     void gotoNextPage();
@@ -61,7 +63,7 @@ private:
     void selectPageUpDown(int summand);
 
 private:
-    OpenPagesModel *m_openPagesModel = nullptr;
+    QAbstractItemModel *m_openPagesModel = nullptr;
     OpenPagesWidget *m_openPagesWidget = nullptr;
 };
 
diff --git a/src/plugins/help/openpageswidget.cpp b/src/plugins/help/openpageswidget.cpp
index 55b55353f24..29c27c6bc50 100644
--- a/src/plugins/help/openpageswidget.cpp
+++ b/src/plugins/help/openpageswidget.cpp
@@ -26,7 +26,6 @@
 #include "openpageswidget.h"
 
 #include "centralwidget.h"
-#include "openpagesmodel.h"
 
 #include <coreplugin/coreconstants.h>
 #include <utils/stringutils.h>
@@ -39,7 +38,7 @@ using namespace Help::Internal;
 
 // -- OpenPagesWidget
 
-OpenPagesWidget::OpenPagesWidget(OpenPagesModel *sourceModel, QWidget *parent)
+OpenPagesWidget::OpenPagesWidget(QAbstractItemModel *sourceModel, QWidget *parent)
     : OpenDocumentsTreeView(parent)
     , m_allowContextMenu(true)
 {
diff --git a/src/plugins/help/openpageswidget.h b/src/plugins/help/openpageswidget.h
index c06cc2bb448..23a7e50199d 100644
--- a/src/plugins/help/openpageswidget.h
+++ b/src/plugins/help/openpageswidget.h
@@ -30,14 +30,12 @@
 namespace Help {
 namespace Internal {
 
-class OpenPagesModel;
-
 class OpenPagesWidget : public Core::OpenDocumentsTreeView
 {
     Q_OBJECT
 
 public:
-    explicit OpenPagesWidget(OpenPagesModel *model, QWidget *parent = nullptr);
+    explicit OpenPagesWidget(QAbstractItemModel *model, QWidget *parent = nullptr);
     ~OpenPagesWidget() override;
 
     void selectCurrentPage();