diff --git a/examples/osgwidgetbox/osgwidgetbox.cpp b/examples/osgwidgetbox/osgwidgetbox.cpp
index cb020969f..fad8b72d8 100644
--- a/examples/osgwidgetbox/osgwidgetbox.cpp
+++ b/examples/osgwidgetbox/osgwidgetbox.cpp
@@ -18,9 +18,10 @@ const unsigned int MASK_3D = 0x0F000000;
 struct ColorWidget: public osgWidget::Widget {
     ColorWidget():
     osgWidget::Widget("", 256.0f, 256.0f) {
+        setEventMask(osgWidget::EVENT_ALL);
     }
 
-    bool mouseEnter(double, double, osgWidget::WindowManager*) {
+    bool mouseEnter(double, double, const osgWidget::WindowManager*) {
         addColor(-osgWidget::Color(0.4f, 0.4f, 0.4f, 0.0f));
         
         // osgWidget::warn() << "enter: " << getColor() << std::endl;
@@ -28,7 +29,7 @@ struct ColorWidget: public osgWidget::Widget {
         return true;
     }
 
-    bool mouseLeave(double, double, osgWidget::WindowManager*) {
+    bool mouseLeave(double, double, const osgWidget::WindowManager*) {
         addColor(osgWidget::Color(0.4f, 0.4f, 0.4f, 0.0f));
         
         // osgWidget::warn() << "leave: " << getColor() << std::endl;
@@ -36,7 +37,7 @@ struct ColorWidget: public osgWidget::Widget {
         return true;
     }
 
-    bool mouseOver(double x, double y, osgWidget::WindowManager*) {
+    bool mouseOver(double x, double y, const osgWidget::WindowManager*) {
         osgWidget::Color c = getImageColorAtPointerXY(x, y);
 
         if(c.a() < 0.001f) {
diff --git a/include/osgWidget/EventInterface b/include/osgWidget/EventInterface
index a5f988fa8..2b67cac9b 100644
--- a/include/osgWidget/EventInterface
+++ b/include/osgWidget/EventInterface
@@ -277,22 +277,22 @@ class OSGWIDGET_EXPORT EventInterface
         // Notify the EventInterface object that is has been focused or unfocused; since
         // this isn't always bound to a mouse event (i.e., if you want to be able to use
         // the TAB key to focus), we need seperate events here.
-        virtual bool focus   (WindowManager*) { return false; }
-        virtual bool unfocus (WindowManager*) { return false; }
+        virtual bool focus   (const WindowManager*) { return false; }
+        virtual bool unfocus (const WindowManager*) { return false; }
 
         // Mouse events, pretty self-explanatory.
-        virtual bool mouseEnter   (double, double, WindowManager*) { return false; }
-        virtual bool mouseOver    (double, double, WindowManager*) { return false; }
-        virtual bool mouseLeave   (double, double, WindowManager*) { return false; }
-        virtual bool mouseDrag    (double, double, WindowManager*) { return false; }
-        virtual bool mousePush    (double, double, WindowManager*) { return false; }
-        virtual bool mouseRelease (double, double, WindowManager*) { return false; }
-        virtual bool mouseScroll  (double, double, WindowManager*) { return false; }
+        virtual bool mouseEnter   (double, double, const WindowManager*) { return false; }
+        virtual bool mouseOver    (double, double, const WindowManager*) { return false; }
+        virtual bool mouseLeave   (double, double, const WindowManager*) { return false; }
+        virtual bool mouseDrag    (double, double, const WindowManager*) { return false; }
+        virtual bool mousePush    (double, double, const WindowManager*) { return false; }
+        virtual bool mouseRelease (double, double, const WindowManager*) { return false; }
+        virtual bool mouseScroll  (double, double, const WindowManager*) { return false; }
 
         // These functions pass the osgGA::GUIEventAdapter::KeySymbol and KeyModMask and,
         // as above, the WindowManager.
-        virtual bool keyDown (int, int, WindowManager*) { return false; }
-        virtual bool keyUp   (int, int, WindowManager*) { return false; }
+        virtual bool keyDown (int, int, const WindowManager*) { return false; }
+        virtual bool keyUp   (int, int, const WindowManager*) { return false; }
 
         void setEventMask(unsigned int mask) {
             _eventMask = mask;