diff --git a/src/widgets/accessible/accessible.pri b/src/widgets/accessible/accessible.pri
index bcdfbd639c4..ac8205b1e3a 100644
--- a/src/widgets/accessible/accessible.pri
+++ b/src/widgets/accessible/accessible.pri
@@ -4,12 +4,12 @@ contains(QT_CONFIG, accessibility) {
     HEADERS += \
         accessible/qaccessiblewidget.h \
         accessible/qaccessiblewidgetfactory_p.h \
-        accessible/complexwidgets.h \
-        accessible/itemviews.h \
-        accessible/qaccessiblemenu.h \
-        accessible/qaccessiblewidgets.h \
-        accessible/rangecontrols.h \
-        accessible/simplewidgets.h
+        accessible/complexwidgets_p.h \
+        accessible/itemviews_p.h \
+        accessible/qaccessiblemenu_p.h \
+        accessible/qaccessiblewidgets_p.h \
+        accessible/rangecontrols_p.h \
+        accessible/simplewidgets_p.h
 
     SOURCES += \
         accessible/qaccessiblewidget.cpp \
diff --git a/src/widgets/accessible/complexwidgets.cpp b/src/widgets/accessible/complexwidgets.cpp
index 60a1329d5e2..6e985c86e8a 100644
--- a/src/widgets/accessible/complexwidgets.cpp
+++ b/src/widgets/accessible/complexwidgets.cpp
@@ -31,7 +31,7 @@
 **
 ****************************************************************************/
 
-#include "complexwidgets.h"
+#include "complexwidgets_p.h"
 
 #include <qaccessible.h>
 #include <qapplication.h>
diff --git a/src/widgets/accessible/complexwidgets.h b/src/widgets/accessible/complexwidgets_p.h
similarity index 94%
rename from src/widgets/accessible/complexwidgets.h
rename to src/widgets/accessible/complexwidgets_p.h
index bd063e75174..8edf996818b 100644
--- a/src/widgets/accessible/complexwidgets.h
+++ b/src/widgets/accessible/complexwidgets_p.h
@@ -34,6 +34,17 @@
 #ifndef COMPLEXWIDGETS_H
 #define COMPLEXWIDGETS_H
 
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
 #include <QtCore/qpointer.h>
 #include <QtWidgets/qaccessiblewidget.h>
 #include <QtWidgets/qabstractitemview.h>
diff --git a/src/widgets/accessible/itemviews.cpp b/src/widgets/accessible/itemviews.cpp
index 4f6cb56060a..6534d51a45e 100644
--- a/src/widgets/accessible/itemviews.cpp
+++ b/src/widgets/accessible/itemviews.cpp
@@ -31,7 +31,7 @@
 **
 ****************************************************************************/
 
-#include "itemviews.h"
+#include "itemviews_p.h"
 
 #include <qheaderview.h>
 #include <qtableview.h>
diff --git a/src/widgets/accessible/itemviews.h b/src/widgets/accessible/itemviews_p.h
similarity index 97%
rename from src/widgets/accessible/itemviews.h
rename to src/widgets/accessible/itemviews_p.h
index c1bd70a3905..a1b6a6db9fc 100644
--- a/src/widgets/accessible/itemviews.h
+++ b/src/widgets/accessible/itemviews_p.h
@@ -34,6 +34,17 @@
 #ifndef ACCESSIBLE_ITEMVIEWS_H
 #define ACCESSIBLE_ITEMVIEWS_H
 
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
 #include "QtCore/qpointer.h"
 #include <QtGui/qaccessible.h>
 #include <QtWidgets/qaccessiblewidget.h>
diff --git a/src/widgets/accessible/qaccessiblemenu.cpp b/src/widgets/accessible/qaccessiblemenu.cpp
index 72eb82b2b73..a0a7852851d 100644
--- a/src/widgets/accessible/qaccessiblemenu.cpp
+++ b/src/widgets/accessible/qaccessiblemenu.cpp
@@ -31,7 +31,7 @@
 **
 ****************************************************************************/
 
-#include "qaccessiblemenu.h"
+#include "qaccessiblemenu_p.h"
 
 #include <qmenu.h>
 #include <qmenubar.h>
diff --git a/src/widgets/accessible/qaccessiblemenu.h b/src/widgets/accessible/qaccessiblemenu_p.h
similarity index 94%
rename from src/widgets/accessible/qaccessiblemenu.h
rename to src/widgets/accessible/qaccessiblemenu_p.h
index 9c7671072d2..b42c852ff19 100644
--- a/src/widgets/accessible/qaccessiblemenu.h
+++ b/src/widgets/accessible/qaccessiblemenu_p.h
@@ -34,6 +34,17 @@
 #ifndef QACCESSIBLEMENU_H
 #define QACCESSIBLEMENU_H
 
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
 #include <QtWidgets/qaccessiblewidget.h>
 #include <QtCore/qpointer.h>
 
diff --git a/src/widgets/accessible/qaccessiblewidgetfactory.cpp b/src/widgets/accessible/qaccessiblewidgetfactory.cpp
index e8b325b93fa..4fa7c894826 100644
--- a/src/widgets/accessible/qaccessiblewidgetfactory.cpp
+++ b/src/widgets/accessible/qaccessiblewidgetfactory.cpp
@@ -31,12 +31,12 @@
 **
 ****************************************************************************/
 
-#include "qaccessiblewidgets.h"
-#include "qaccessiblemenu.h"
-#include "simplewidgets.h"
-#include "rangecontrols.h"
-#include "complexwidgets.h"
-#include "itemviews.h"
+#include "qaccessiblewidgets_p.h"
+#include "qaccessiblemenu_p.h"
+#include "simplewidgets_p.h"
+#include "rangecontrols_p.h"
+#include "complexwidgets_p.h"
+#include "itemviews_p.h"
 
 #include <qpushbutton.h>
 #include <qtoolbutton.h>
diff --git a/src/widgets/accessible/qaccessiblewidgetfactory_p.h b/src/widgets/accessible/qaccessiblewidgetfactory_p.h
index b3f9d8a2511..caa37dcf818 100644
--- a/src/widgets/accessible/qaccessiblewidgetfactory_p.h
+++ b/src/widgets/accessible/qaccessiblewidgetfactory_p.h
@@ -36,6 +36,17 @@
 #ifndef QACCESSIBLEWIDGETFACTORY_H
 #define QACCESSIBLEWIDGETFACTORY_H
 
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
 QT_BEGIN_NAMESPACE
 
 QAccessibleInterface *qAccessibleFactory(const QString &classname, QObject *object);
diff --git a/src/widgets/accessible/qaccessiblewidgets.cpp b/src/widgets/accessible/qaccessiblewidgets.cpp
index a2bf14b25b6..604c754ea1b 100644
--- a/src/widgets/accessible/qaccessiblewidgets.cpp
+++ b/src/widgets/accessible/qaccessiblewidgets.cpp
@@ -31,7 +31,7 @@
 **
 ****************************************************************************/
 
-#include "qaccessiblewidgets.h"
+#include "qaccessiblewidgets_p.h"
 #include "qabstracttextdocumentlayout.h"
 #include "qapplication.h"
 #include "qclipboard.h"
diff --git a/src/widgets/accessible/qaccessiblewidgets.h b/src/widgets/accessible/qaccessiblewidgets_p.h
similarity index 97%
rename from src/widgets/accessible/qaccessiblewidgets.h
rename to src/widgets/accessible/qaccessiblewidgets_p.h
index 53f8c2c6035..4bdc229578b 100644
--- a/src/widgets/accessible/qaccessiblewidgets.h
+++ b/src/widgets/accessible/qaccessiblewidgets_p.h
@@ -34,6 +34,17 @@
 #ifndef QACCESSIBLEWIDGETS_H
 #define QACCESSIBLEWIDGETS_H
 
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
 #include <QtWidgets/qaccessiblewidget.h>
 
 #ifndef QT_NO_ACCESSIBILITY
diff --git a/src/widgets/accessible/rangecontrols.cpp b/src/widgets/accessible/rangecontrols.cpp
index 002d4a9ef46..0607a352695 100644
--- a/src/widgets/accessible/rangecontrols.cpp
+++ b/src/widgets/accessible/rangecontrols.cpp
@@ -31,7 +31,7 @@
 **
 ****************************************************************************/
 
-#include "rangecontrols.h"
+#include "rangecontrols_p.h"
 
 #include <qslider.h>
 #include <qdial.h>
@@ -47,7 +47,7 @@
 #include <qmath.h>
 #include <private/qmath_p.h>
 
-#include "simplewidgets.h" // let spinbox use line edit's interface
+#include "simplewidgets_p.h" // let spinbox use line edit's interface
 
 QT_BEGIN_NAMESPACE
 
diff --git a/src/widgets/accessible/rangecontrols.h b/src/widgets/accessible/rangecontrols_p.h
similarity index 96%
rename from src/widgets/accessible/rangecontrols.h
rename to src/widgets/accessible/rangecontrols_p.h
index 11d4435e9d2..32c6d6985fe 100644
--- a/src/widgets/accessible/rangecontrols.h
+++ b/src/widgets/accessible/rangecontrols_p.h
@@ -34,6 +34,17 @@
 #ifndef RANGECONTROLS_H
 #define RANGECONTROLS_H
 
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
 #include <QtWidgets/qaccessiblewidget.h>
 
 QT_BEGIN_NAMESPACE
diff --git a/src/widgets/accessible/simplewidgets.cpp b/src/widgets/accessible/simplewidgets.cpp
index b08c21939ae..065c618cf7e 100644
--- a/src/widgets/accessible/simplewidgets.cpp
+++ b/src/widgets/accessible/simplewidgets.cpp
@@ -31,7 +31,7 @@
 **
 ****************************************************************************/
 
-#include "simplewidgets.h"
+#include "simplewidgets_p.h"
 
 #include <qabstractbutton.h>
 #include <qcheckbox.h>
diff --git a/src/widgets/accessible/simplewidgets.h b/src/widgets/accessible/simplewidgets_p.h
similarity index 96%
rename from src/widgets/accessible/simplewidgets.h
rename to src/widgets/accessible/simplewidgets_p.h
index 0dfd9f79c89..c2e904273fa 100644
--- a/src/widgets/accessible/simplewidgets.h
+++ b/src/widgets/accessible/simplewidgets_p.h
@@ -34,6 +34,17 @@
 #ifndef SIMPLEWIDGETS_H
 #define SIMPLEWIDGETS_H
 
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
 #include <QtCore/qcoreapplication.h>
 #include <QtWidgets/qaccessiblewidget.h>