diff --git a/modules/juce_gui_basics/native/juce_win32_Windowing.cpp b/modules/juce_gui_basics/native/juce_win32_Windowing.cpp
index ddea196e7d..47963d00ec 100644
--- a/modules/juce_gui_basics/native/juce_win32_Windowing.cpp
+++ b/modules/juce_gui_basics/native/juce_win32_Windowing.cpp
@@ -1404,12 +1404,13 @@ private:
 
     static BOOL CALLBACK clipChildWindowCallback (HWND hwnd, LPARAM context)
     {
-        RECT childPos, parentPos;
+        RECT childPos;
         GetWindowRect (hwnd, &childPos);
-        GetWindowRect (GetParent (hwnd), &parentPos);
+        POINT pos = { childPos.left, childPos.top };
+        ScreenToClient (GetParent (hwnd), &pos);
 
-        ((RectangleList<int>*) context)->subtract (Rectangle<int> (childPos.left   - parentPos.left,
-                                                                   childPos.top    - parentPos.top,
+        ((RectangleList<int>*) context)->subtract (Rectangle<int> (pos.x,
+                                                                   pos.y,
                                                                    childPos.right  - childPos.left,
                                                                    childPos.bottom - childPos.top));
         return TRUE;
diff --git a/modules/juce_opengl/opengl/juce_OpenGLContext.cpp b/modules/juce_opengl/opengl/juce_OpenGLContext.cpp
index 88800fe3b5..c1d63d83d4 100644
--- a/modules/juce_opengl/opengl/juce_OpenGLContext.cpp
+++ b/modules/juce_opengl/opengl/juce_OpenGLContext.cpp
@@ -185,18 +185,21 @@ public:
 
     void updateViewportSize (bool canTriggerUpdate)
     {
-        const double newScale = Desktop::getInstance().getDisplays()
-                                    .getDisplayContaining (component.getScreenBounds().getCentre()).scale;
-
-        Rectangle<int> newArea (component.getLocalBounds() * newScale);
-
-        if (scale != newScale || viewportArea != newArea)
+        if (ComponentPeer* peer = component.getPeer())
         {
-            scale = newScale;
-            viewportArea = newArea;
+            Rectangle<int> newArea (peer->getAreaCoveredBy (component).withPosition (0, 0));
 
-            if (canTriggerUpdate)
-                invalidateAll();
+            const double newScale = Desktop::getInstance().getDisplays()
+                                        .getDisplayContaining (component.getScreenBounds().getCentre()).scale;
+
+            if (scale != newScale || viewportArea != newArea)
+            {
+                scale = newScale;
+                viewportArea = newArea;
+
+                if (canTriggerUpdate)
+                    invalidateAll();
+            }
         }
     }