diff --git a/modules/juce_gui_basics/native/juce_Windowing_windows.cpp b/modules/juce_gui_basics/native/juce_Windowing_windows.cpp
index 047c32cfda..c89140b03f 100644
--- a/modules/juce_gui_basics/native/juce_Windowing_windows.cpp
+++ b/modules/juce_gui_basics/native/juce_Windowing_windows.cpp
@@ -1973,6 +1973,8 @@ public:
         if (wParam & MK_LBUTTON)   mouseMods |= ModifierKeys::leftButtonModifier;
         if (wParam & MK_RBUTTON)   mouseMods |= ModifierKeys::rightButtonModifier;
         if (wParam & MK_MBUTTON)   mouseMods |= ModifierKeys::middleButtonModifier;
+        if (wParam & MK_XBUTTON1)  mouseMods |= ModifierKeys::backButtonModifier;
+        if (wParam & MK_XBUTTON2)  mouseMods |= ModifierKeys::forwardButtonModifier;
 
         ModifierKeys::currentModifiers = ModifierKeys::getCurrentModifiers().withoutMouseButtons().withFlags (mouseMods);
         updateKeyModifiers();
@@ -4056,12 +4058,14 @@ private:
             case WM_LBUTTONDOWN:
             case WM_MBUTTONDOWN:
             case WM_RBUTTONDOWN:
+            case WM_XBUTTONDOWN:
                 doMouseDown (lParam, wParam);
                 return 0;
 
             case WM_LBUTTONUP:
             case WM_MBUTTONUP:
             case WM_RBUTTONUP:
+            case WM_XBUTTONUP:
                 doMouseUp (getPointFromLocalLParam (lParam), wParam);
                 return 0;