diff --git a/modules/juce_events/native/juce_win32_Messaging.cpp b/modules/juce_events/native/juce_win32_Messaging.cpp
index d9eabdf5cd..43c9152069 100644
--- a/modules/juce_events/native/juce_win32_Messaging.cpp
+++ b/modules/juce_events/native/juce_win32_Messaging.cpp
@@ -25,40 +25,164 @@ namespace juce
 
 extern HWND juce_messageWindowHandle;
 
+#if JUCE_MODULE_AVAILABLE_juce_audio_plugin_client && JucePlugin_Build_Unity
+ bool juce_isRunningInUnity();
+#endif
+
+#if JUCE_MODULE_AVAILABLE_juce_gui_extra
+ LRESULT juce_offerEventToActiveXControl (::MSG&);
+#endif
+
 using CheckEventBlockedByModalComps = bool (*)(const MSG&);
 CheckEventBlockedByModalComps isEventBlockedByModalComps = nullptr;
 
 using SettingChangeCallbackFunc = void (*)(void);
 SettingChangeCallbackFunc settingChangeCallback = nullptr;
 
-#if JUCE_MODULE_AVAILABLE_juce_audio_plugin_client && JucePlugin_Build_Unity
- bool juce_isRunningInUnity();
-#endif
-
 //==============================================================================
-namespace WindowsMessageHelpers
+class InternalMessageQueue
 {
-    const unsigned int customMessageID = WM_USER + 123;
-    const unsigned int broadcastMessageMagicNumber = 0xc403;
-
-    const TCHAR messageWindowName[] = _T("JUCEWindow");
-    std::unique_ptr<HiddenMessageWindow> messageWindow;
-
-    void dispatchMessageFromLParam (LPARAM lParam)
+public:
+    InternalMessageQueue()
     {
-        if (auto message = reinterpret_cast<MessageManager::MessageBase*> (lParam))
-        {
-            JUCE_TRY
-            {
-                message->messageCallback();
-            }
-            JUCE_CATCH_EXCEPTION
+        messageWindow = std::make_unique<HiddenMessageWindow> (messageWindowName, (WNDPROC) messageWndProc);
+        juce_messageWindowHandle = messageWindow->getHWND();
+    }
 
-            message->decReferenceCount();
+    ~InternalMessageQueue()
+    {
+        juce_messageWindowHandle = 0;
+        clearSingletonInstance();
+    }
+
+    JUCE_DECLARE_SINGLETON (InternalMessageQueue, false)
+
+    //==============================================================================
+    void broadcastMessage (const String& message)
+    {
+        auto localCopy = message;
+
+        Array<HWND> windows;
+        EnumWindows (&broadcastEnumWindowProc, (LPARAM) &windows);
+
+        for (int i = windows.size(); --i >= 0;)
+        {
+            COPYDATASTRUCT data;
+            data.dwData = broadcastMessageMagicNumber;
+            data.cbData = (localCopy.length() + 1) * sizeof (CharPointer_UTF32::CharType);
+            data.lpData = (void*) localCopy.toUTF32().getAddress();
+
+            DWORD_PTR result;
+            SendMessageTimeout (windows.getUnchecked (i), WM_COPYDATA,
+                                (WPARAM) juce_messageWindowHandle,
+                                (LPARAM) &data,
+                                SMTO_BLOCK | SMTO_ABORTIFHUNG, 8000, &result);
         }
     }
 
-    BOOL CALLBACK broadcastEnumWindowProc (HWND hwnd, LPARAM lParam)
+    bool postMessage (MessageManager::MessageBase* message)
+    {
+        message->incReferenceCount();
+
+        #if JUCE_MODULE_AVAILABLE_juce_audio_plugin_client && JucePlugin_Build_Unity
+         if (juce_isRunningInUnity())
+             return SendNotifyMessage (juce_messageWindowHandle, customMessageID, 0, (LPARAM) message) != 0;
+        #endif
+
+         if (PostMessage (juce_messageWindowHandle, customMessageID, 0, (LPARAM) message) != 0)
+             return true;
+
+        if (GetLastError() == ERROR_NOT_ENOUGH_QUOTA)
+        {
+            const ScopedLock sl (lock);
+            overflowQueue.add (message);
+            message->decReferenceCount();
+
+            return true;
+        }
+
+        return false;
+    }
+
+    bool dispatchNextMessage (bool returnIfNoPendingMessages)
+    {
+        MSG m;
+
+        if (returnIfNoPendingMessages && ! PeekMessage (&m, (HWND) 0, 0, 0, PM_NOREMOVE) && overflowQueue.size() == 0)
+            return false;
+
+        if (GetMessage (&m, (HWND) 0, 0, 0) >= 0)
+        {
+           #if JUCE_MODULE_AVAILABLE_juce_gui_extra
+            if (juce_offerEventToActiveXControl (m) != S_FALSE)
+                return true;
+           #endif
+
+            if (m.message == customMessageID && m.hwnd == juce_messageWindowHandle)
+            {
+                dispatchMessageFromLParam (m.lParam);
+            }
+            else if (m.message == WM_QUIT)
+            {
+                if (auto* app = JUCEApplicationBase::getInstance())
+                    app->systemRequestedQuit();
+            }
+            else if (isEventBlockedByModalComps == nullptr || ! isEventBlockedByModalComps (m))
+            {
+                if ((m.message == WM_LBUTTONDOWN || m.message == WM_RBUTTONDOWN)
+                      && ! JuceWindowIdentifier::isJUCEWindow (m.hwnd))
+                {
+                    // if it's someone else's window being clicked on, and the focus is
+                    // currently on a juce window, pass the kb focus over..
+                    auto currentFocus = GetFocus();
+
+                    if (currentFocus == 0 || JuceWindowIdentifier::isJUCEWindow (currentFocus))
+                        SetFocus (m.hwnd);
+                }
+
+                TranslateMessage (&m);
+                DispatchMessage (&m);
+            }
+        }
+
+        dispatchOverflowMessages();
+
+        return true;
+    }
+
+private:
+    //==============================================================================
+    static LRESULT CALLBACK messageWndProc (HWND h, UINT message, WPARAM wParam, LPARAM lParam) noexcept
+    {
+        if (h == juce_messageWindowHandle)
+        {
+            if (message == customMessageID)
+            {
+                // (These are trapped early in our dispatch loop, but must also be checked
+                // here in case some 3rd-party code is running the dispatch loop).
+                dispatchMessageFromLParam (lParam);
+
+                if (auto* queue = InternalMessageQueue::getInstanceWithoutCreating())
+                    queue->dispatchOverflowMessages();
+
+                return 0;
+            }
+
+            if (message == WM_COPYDATA)
+            {
+                handleBroadcastMessage (reinterpret_cast<const COPYDATASTRUCT*> (lParam));
+                return 0;
+            }
+
+            if (message == WM_SETTINGCHANGE)
+                if (settingChangeCallback != nullptr)
+                    settingChangeCallback();
+        }
+
+        return DefWindowProc (h, message, wParam, lParam);
+    }
+
+    static BOOL CALLBACK broadcastEnumWindowProc (HWND hwnd, LPARAM lParam)
     {
         if (hwnd != juce_messageWindowHandle)
         {
@@ -72,7 +196,21 @@ namespace WindowsMessageHelpers
         return TRUE;
     }
 
-    void handleBroadcastMessage (const COPYDATASTRUCT* data)
+    static void dispatchMessageFromLParam (LPARAM lParam)
+    {
+        if (auto message = reinterpret_cast<MessageManager::MessageBase*> (lParam))
+        {
+            JUCE_TRY
+            {
+                message->messageCallback();
+            }
+            JUCE_CATCH_EXCEPTION
+
+            message->decReferenceCount();
+        }
+    }
+
+    static void handleBroadcastMessage (const COPYDATASTRUCT* data)
     {
         if (data != nullptr && data->dwData == broadcastMessageMagicNumber)
         {
@@ -90,132 +228,74 @@ namespace WindowsMessageHelpers
         }
     }
 
-    //==============================================================================
-    LRESULT CALLBACK messageWndProc (HWND h, UINT message, WPARAM wParam, LPARAM lParam) noexcept
+    void dispatchOverflowMessages()
     {
-        if (h == juce_messageWindowHandle)
+        const ScopedLock sl (lock);
+
+        for (int i = 0; i < overflowQueue.size(); ++i)
         {
-            if (message == customMessageID)
-            {
-                // (These are trapped early in our dispatch loop, but must also be checked
-                // here in case some 3rd-party code is running the dispatch loop).
-                dispatchMessageFromLParam (lParam);
-                return 0;
-            }
-
-            if (message == WM_COPYDATA)
-            {
-                handleBroadcastMessage (reinterpret_cast<const COPYDATASTRUCT*> (lParam));
-                return 0;
-            }
-
-            if (message == WM_SETTINGCHANGE)
-                if (settingChangeCallback != nullptr)
-                    settingChangeCallback();
+            auto message = overflowQueue.getUnchecked (i);
+            message->incReferenceCount();
+            dispatchMessageFromLParam ((LPARAM) message.get());
         }
 
-        return DefWindowProc (h, message, wParam, lParam);
+        overflowQueue.clear();
     }
-}
 
-#if JUCE_MODULE_AVAILABLE_juce_gui_extra
-LRESULT juce_offerEventToActiveXControl (::MSG&);
-#endif
+    //==============================================================================
+    static constexpr unsigned int customMessageID = WM_USER + 123;
+    static constexpr unsigned int broadcastMessageMagicNumber = 0xc403;
+    static const TCHAR messageWindowName[];
+
+    std::unique_ptr<HiddenMessageWindow> messageWindow;
+
+    CriticalSection lock;
+    ReferenceCountedArray<MessageManager::MessageBase> overflowQueue;
+
+    //==============================================================================
+    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (InternalMessageQueue)
+};
+
+JUCE_IMPLEMENT_SINGLETON (InternalMessageQueue)
+
+const TCHAR InternalMessageQueue::messageWindowName[] = _T("JUCEWindow");
 
 //==============================================================================
 bool MessageManager::dispatchNextMessageOnSystemQueue (bool returnIfNoPendingMessages)
 {
-    using namespace WindowsMessageHelpers;
-    MSG m;
+    if (auto* queue = InternalMessageQueue::getInstanceWithoutCreating())
+        return queue->dispatchNextMessage (returnIfNoPendingMessages);
 
-    if (returnIfNoPendingMessages && ! PeekMessage (&m, (HWND) 0, 0, 0, PM_NOREMOVE))
-        return false;
-
-    if (GetMessage (&m, (HWND) 0, 0, 0) >= 0)
-    {
-       #if JUCE_MODULE_AVAILABLE_juce_gui_extra
-        if (juce_offerEventToActiveXControl (m) != S_FALSE)
-            return true;
-       #endif
-
-        if (m.message == customMessageID && m.hwnd == juce_messageWindowHandle)
-        {
-            dispatchMessageFromLParam (m.lParam);
-        }
-        else if (m.message == WM_QUIT)
-        {
-            if (auto* app = JUCEApplicationBase::getInstance())
-                app->systemRequestedQuit();
-        }
-        else if (isEventBlockedByModalComps == nullptr || ! isEventBlockedByModalComps (m))
-        {
-            if ((m.message == WM_LBUTTONDOWN || m.message == WM_RBUTTONDOWN)
-                  && ! JuceWindowIdentifier::isJUCEWindow (m.hwnd))
-            {
-                // if it's someone else's window being clicked on, and the focus is
-                // currently on a juce window, pass the kb focus over..
-                auto currentFocus = GetFocus();
-
-                if (currentFocus == 0 || JuceWindowIdentifier::isJUCEWindow (currentFocus))
-                    SetFocus (m.hwnd);
-            }
-
-            TranslateMessage (&m);
-            DispatchMessage (&m);
-        }
-    }
-
-    return true;
+    return false;
 }
 
 bool MessageManager::postMessageToSystemQueue (MessageManager::MessageBase* const message)
 {
-    message->incReferenceCount();
+    if (auto* queue = InternalMessageQueue::getInstanceWithoutCreating())
+    {
+        queue->postMessage (message);
+        return true;
+    }
 
-   #if JUCE_MODULE_AVAILABLE_juce_audio_plugin_client && JucePlugin_Build_Unity
-    if (juce_isRunningInUnity())
-        return SendNotifyMessage (juce_messageWindowHandle, WindowsMessageHelpers::customMessageID, 0, (LPARAM) message) != 0;
-   #endif
-
-    return PostMessage (juce_messageWindowHandle, WindowsMessageHelpers::customMessageID, 0, (LPARAM) message) != 0;
+    return false;
 }
 
 void MessageManager::broadcastMessage (const String& value)
 {
-    auto localCopy = value;
-
-    Array<HWND> windows;
-    EnumWindows (&WindowsMessageHelpers::broadcastEnumWindowProc, (LPARAM) &windows);
-
-    for (int i = windows.size(); --i >= 0;)
-    {
-        COPYDATASTRUCT data;
-        data.dwData = WindowsMessageHelpers::broadcastMessageMagicNumber;
-        data.cbData = (localCopy.length() + 1) * sizeof (CharPointer_UTF32::CharType);
-        data.lpData = (void*) localCopy.toUTF32().getAddress();
-
-        DWORD_PTR result;
-        SendMessageTimeout (windows.getUnchecked (i), WM_COPYDATA,
-                            (WPARAM) juce_messageWindowHandle,
-                            (LPARAM) &data,
-                            SMTO_BLOCK | SMTO_ABORTIFHUNG, 8000, &result);
-    }
+    if (auto* queue = InternalMessageQueue::getInstanceWithoutCreating())
+        queue->broadcastMessage (value);
 }
 
 //==============================================================================
 void MessageManager::doPlatformSpecificInitialisation()
 {
     OleInitialize (0);
-
-    using namespace WindowsMessageHelpers;
-    messageWindow.reset (new HiddenMessageWindow (messageWindowName, (WNDPROC) messageWndProc));
-    juce_messageWindowHandle = messageWindow->getHWND();
+    InternalMessageQueue::getInstance();
 }
 
 void MessageManager::doPlatformSpecificShutdown()
 {
-    WindowsMessageHelpers::messageWindow = nullptr;
-
+    InternalMessageQueue::deleteInstance();
     OleUninitialize();
 }
 
diff --git a/modules/juce_gui_basics/native/juce_win32_Windowing.cpp b/modules/juce_gui_basics/native/juce_win32_Windowing.cpp
index 455ceb3990..242b5cd6db 100644
--- a/modules/juce_gui_basics/native/juce_win32_Windowing.cpp
+++ b/modules/juce_gui_basics/native/juce_win32_Windowing.cpp
@@ -56,7 +56,7 @@ extern void juce_repeatLastProcessPriority();
 extern void juce_checkCurrentlyFocusedTopLevelWindow();  // in juce_TopLevelWindow.cpp
 extern bool juce_isRunningInWine();
 
-typedef bool (*CheckEventBlockedByModalComps) (const MSG&);
+using CheckEventBlockedByModalComps = bool (*)(const MSG&);
 extern CheckEventBlockedByModalComps isEventBlockedByModalComps;
 
 static bool shouldDeactivateTitleBar = true;
@@ -496,7 +496,7 @@ static double getGlobalDPI()
 #endif
 
 //==============================================================================
-typedef void (*SettingChangeCallbackFunc) (void);
+using SettingChangeCallbackFunc = void (*)(void);
 extern SettingChangeCallbackFunc settingChangeCallback;
 
 //==============================================================================