diff --git a/mkspecs/features/create_cmake.prf b/mkspecs/features/create_cmake.prf
index 29c8cadfff0..8c8079b3bdb 100644
--- a/mkspecs/features/create_cmake.prf
+++ b/mkspecs/features/create_cmake.prf
@@ -1,3 +1,13 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
 
 defineReplace(cmakeModuleName) {
     _module = $$1
diff --git a/mkspecs/features/dbuscommon.pri b/mkspecs/features/dbuscommon.pri
index fce2d049675..4608fb6ca24 100644
--- a/mkspecs/features/dbuscommon.pri
+++ b/mkspecs/features/dbuscommon.pri
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 load(moc)
 qtPrepareTool(QMAKE_QDBUSXML2CPP, qdbusxml2cpp)
 
diff --git a/mkspecs/features/qml1_module.prf b/mkspecs/features/qml1_module.prf
index 8bacddc5493..33c3e44808b 100644
--- a/mkspecs/features/qml1_module.prf
+++ b/mkspecs/features/qml1_module.prf
@@ -1,2 +1,13 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 CONFIG += qml1_target
 load(qml_module)
diff --git a/mkspecs/features/qml1_plugin.prf b/mkspecs/features/qml1_plugin.prf
index 2914c78ea38..cb1f0ce2674 100644
--- a/mkspecs/features/qml1_plugin.prf
+++ b/mkspecs/features/qml1_plugin.prf
@@ -1,2 +1,13 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 CONFIG += qml1_target
 load(qml_plugin)
diff --git a/mkspecs/features/qml_module.prf b/mkspecs/features/qml_module.prf
index a452592c9b7..e7d0b386b19 100644
--- a/mkspecs/features/qml_module.prf
+++ b/mkspecs/features/qml_module.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 equals(TEMPLATE, app): TEMPLATE = aux
 
 isEmpty(TARGETPATH): error("Must set TARGETPATH (QML import name)")
diff --git a/mkspecs/features/qml_plugin.prf b/mkspecs/features/qml_plugin.prf
index c700dda41f5..7abd372e497 100644
--- a/mkspecs/features/qml_plugin.prf
+++ b/mkspecs/features/qml_plugin.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 load(qt_build_config)
 
 TEMPLATE = lib
diff --git a/mkspecs/features/qt_build_config.prf b/mkspecs/features/qt_build_config.prf
index df07630ffa5..48d6001aa98 100644
--- a/mkspecs/features/qt_build_config.prf
+++ b/mkspecs/features/qt_build_config.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 !contains(QMAKE_INTERNAL_INCLUDED_FILES, .*qmodule\\.pri) {
     QMAKE_QT_MODULE = $$[QT_HOST_DATA/get]/mkspecs/qmodule.pri
     !exists($$QMAKE_QT_MODULE)|!include($$QMAKE_QT_MODULE, "", true) {
diff --git a/mkspecs/features/qt_build_paths.prf b/mkspecs/features/qt_build_paths.prf
index 5f6f08c3db3..123c87de3bf 100644
--- a/mkspecs/features/qt_build_paths.prf
+++ b/mkspecs/features/qt_build_paths.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 # Find the module's source root dir.
 isEmpty(_QMAKE_CONF_): error("Project has no top-level .qmake.conf file.")
 MODULE_PROFILE_DIR = $$dirname(_QMAKE_CONF_)
diff --git a/mkspecs/features/qt_docs.prf b/mkspecs/features/qt_docs.prf
index d195004077e..99759c6da19 100644
--- a/mkspecs/features/qt_docs.prf
+++ b/mkspecs/features/qt_docs.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 !exists($$QMAKE_DOCS): error("Cannot find documentation specification file $$QMAKE_DOCS")
 
 load(qt_build_paths)
diff --git a/mkspecs/features/qt_docs_targets.prf b/mkspecs/features/qt_docs_targets.prf
index 1af9fd9019b..89f080cc5e3 100644
--- a/mkspecs/features/qt_docs_targets.prf
+++ b/mkspecs/features/qt_docs_targets.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 DOC_TARGETS = \
     install_html_docs uninstall_html_docs \
     install_qch_docs uninstall_qch_docs \
diff --git a/mkspecs/features/qt_example_installs.prf b/mkspecs/features/qt_example_installs.prf
index de1176ef965..54174699092 100644
--- a/mkspecs/features/qt_example_installs.prf
+++ b/mkspecs/features/qt_example_installs.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 probase = $$relative_path($$_PRO_FILE_PWD_, $$dirname(_QMAKE_CONF_)/examples)
 !isEmpty(probase):!contains(probase, ^\\..*) {
     for(ex, EXAMPLE_FILES): \
diff --git a/mkspecs/features/qt_installs.prf b/mkspecs/features/qt_installs.prf
index 0e860cccca3..cc720ac8c05 100644
--- a/mkspecs/features/qt_installs.prf
+++ b/mkspecs/features/qt_installs.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 #library
 !qt_no_install_library {
     win32 {
diff --git a/mkspecs/features/qt_module.prf b/mkspecs/features/qt_module.prf
index ad8d9aab558..cb799711c98 100644
--- a/mkspecs/features/qt_module.prf
+++ b/mkspecs/features/qt_module.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 !no_qt_module_warning:!contains(QMAKE_INTERNAL_INCLUDED_FILES, .*qmodule\\.pri) {
     QMAKE_ACTUAL_PRO_FILE = $$basename(_PRO_FILE_)
     isEmpty(QMAKE_ACTUAL_PRO_FILE): QMAKE_ACTUAL_PRO_FILE=.pro
diff --git a/mkspecs/features/qt_module_fwdpri.prf b/mkspecs/features/qt_module_fwdpri.prf
index 0b203b5a903..ce0b09d6169 100644
--- a/mkspecs/features/qt_module_fwdpri.prf
+++ b/mkspecs/features/qt_module_fwdpri.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 !build_pass {
 
     load(qt_build_paths)
diff --git a/mkspecs/features/qt_module_headers.prf b/mkspecs/features/qt_module_headers.prf
index 6acff234608..10d3fe3c0b1 100644
--- a/mkspecs/features/qt_module_headers.prf
+++ b/mkspecs/features/qt_module_headers.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 load(qt_build_paths)
 
 !build_pass {
diff --git a/mkspecs/features/qt_parts.prf b/mkspecs/features/qt_parts.prf
index 75fa2966bc1..12ba312bcd8 100644
--- a/mkspecs/features/qt_parts.prf
+++ b/mkspecs/features/qt_parts.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 load(qt_build_config)
 
 TEMPLATE = subdirs
diff --git a/mkspecs/features/qt_plugin.prf b/mkspecs/features/qt_plugin.prf
index f547e2d1eba..e58a6d2679b 100644
--- a/mkspecs/features/qt_plugin.prf
+++ b/mkspecs/features/qt_plugin.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 load(qt_build_paths)
 
 isEmpty(PLUGIN_TYPE): error("PLUGIN_TYPE (plugins/ subdirectory) needs to be defined.")
diff --git a/mkspecs/features/qt_tool.prf b/mkspecs/features/qt_tool.prf
index 3510582c8e7..f6654797953 100644
--- a/mkspecs/features/qt_tool.prf
+++ b/mkspecs/features/qt_tool.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 TEMPLATE = app
 
 load(qt_build_paths)
diff --git a/mkspecs/features/resolve_target.prf b/mkspecs/features/resolve_target.prf
index 455dd3b985a..c60faf22c0c 100644
--- a/mkspecs/features/resolve_target.prf
+++ b/mkspecs/features/resolve_target.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 QMAKE_RESOLVED_TARGET = $$absolute_path($$DESTDIR, $$OUT_PWD)/
 
 win32 {
diff --git a/mkspecs/features/simd.prf b/mkspecs/features/simd.prf
index 6d729a66a76..b430e59ff08 100644
--- a/mkspecs/features/simd.prf
+++ b/mkspecs/features/simd.prf
@@ -1,3 +1,14 @@
+#
+#  W A R N I N G
+#  -------------
+#
+# This file is not part of the Qt API.  It exists purely as an
+# implementation detail.  It may change from version to version
+# without notice, or even be removed.
+#
+# We mean it.
+#
+
 # Get the SIMD flags
 load(qt_build_config)