diff --git a/doc/global/qt-cpp-defines.qdocconf b/doc/global/qt-cpp-defines.qdocconf
index 5c762083a27..c2a267d08e8 100644
--- a/doc/global/qt-cpp-defines.qdocconf
+++ b/doc/global/qt-cpp-defines.qdocconf
@@ -162,6 +162,7 @@ Cpp.ignoretokens        += \
                           QT_FASTCALL \
                           QT_MUTEX_LOCK_NOEXCEPT \
                           QT_POPCOUNT_CONSTEXPR \
+                          QT_POST_CXX17_API_IN_EXPORTED_CLASS \
                           QT_SIZEPOLICY_CONSTEXPR \
                           QT_WARNING_DISABLE_DEPRECATED \
                           QT_WARNING_PUSH \
diff --git a/src/corelib/global/qcompilerdetection.h b/src/corelib/global/qcompilerdetection.h
index f6add04fbab..1c17e8b7a04 100644
--- a/src/corelib/global/qcompilerdetection.h
+++ b/src/corelib/global/qcompilerdetection.h
@@ -1206,6 +1206,26 @@
  */
 #define Q_WEAK_OVERLOAD template <typename = void>
 
+/*
+ * If one wants to add functions that use post-C++17 APIs, one needs to:
+ *
+ * 1) make them fully inline; and
+ * 2) guard them using the necessary feature-testing macros.
+ *
+ * This decouples the C++ version used to build Qt with the one used by
+ * end-user applications; Qt and the application can either choose any C++
+ * version.
+ *
+ * A problem arises on MSVC for member functions of exported classes. Client
+ * code that tries to use such a function will see it as exported, and simply
+ * try to consume the function's *symbol*. However, if Qt has been built in
+ * C++17, it won't have such a symbol, and linking will fail.
+ *
+ * The workaround: declare such functions as function templates.
+ * (Obviously a function template does not need this marker.)
+*/
+#define QT_POST_CXX17_API_IN_EXPORTED_CLASS template <typename = void>
+
 /*
  * Warning/diagnostic handling
  */