diff --git a/src/disposable.h b/src/disposable.h
index 0704b17..e580ce1 100644
--- a/src/disposable.h
+++ b/src/disposable.h
@@ -42,15 +42,7 @@ struct DisposeWatch
 {
 	typedef void (C::*NotifyFun)();
 
-	/* The object owning the prop (and this helper) */
-	C *owner;
-	/* Optional notify method */
-	const NotifyFun notify;
-	/* Location of the prop pointer inside the owner */
-	P *&propLocation;
-	sigc::connection dispCon;
-
-	DisposeWatch(C *owner, P *&propLocation, NotifyFun notify = 0)
+	DisposeWatch(C &owner, P *&propLocation, NotifyFun notify = 0)
 	    : owner(owner),
 	      notify(notify),
 	      propLocation(propLocation)
@@ -74,13 +66,21 @@ struct DisposeWatch
 	}
 
 private:
+	/* The object owning the prop (and this helper) */
+	C  &owner;
+	/* Optional notify method */
+	const NotifyFun notify;
+	/* Location of the prop pointer inside the owner */
+	P * &propLocation;
+	sigc::connection dispCon;
+
 	void onDisposed()
 	{
 		dispCon.disconnect();
 		propLocation = 0;
 
 		if (notify)
-			(owner->*notify)();
+			(owner.*notify)();
 	}
 };
 
diff --git a/src/plane.cpp b/src/plane.cpp
index 2f6ee55..3729016 100644
--- a/src/plane.cpp
+++ b/src/plane.cpp
@@ -67,7 +67,7 @@ struct PlanePrivate
 
 	PlanePrivate()
 	    : bitmap(0),
-	      bitmapWatch(this, bitmap),
+	      bitmapWatch(*this, bitmap),
 	      opacity(255),
 	      blendType(BlendNormal),
 	      color(&tmp.color),
diff --git a/src/sprite.cpp b/src/sprite.cpp
index a2f9197..6a1913e 100644
--- a/src/sprite.cpp
+++ b/src/sprite.cpp
@@ -89,7 +89,7 @@ struct SpritePrivate
 
 	SpritePrivate()
 	    : bitmap(0),
-	      bitmapWatch(this, bitmap),
+	      bitmapWatch(*this, bitmap),
 	      srcRect(&tmp.rect),
 	      mirrored(false),
 	      bushDepth(0),
diff --git a/src/tilemap.cpp b/src/tilemap.cpp
index 09d5136..f65df29 100644
--- a/src/tilemap.cpp
+++ b/src/tilemap.cpp
@@ -355,7 +355,7 @@ struct TilemapPrivate
 	TilemapPrivate(Viewport *viewport)
 	    : viewport(viewport),
 	      tileset(0),
-	      tilesetWatch(this, tileset),
+	      tilesetWatch(*this, tileset),
 	      mapData(0),
 	      flashData(0),
 	      priorities(0),
diff --git a/src/window.cpp b/src/window.cpp
index 7dc46ce..6f985fd 100644
--- a/src/window.cpp
+++ b/src/window.cpp
@@ -250,9 +250,9 @@ struct WindowPrivate
 
 	WindowPrivate(Viewport *viewport = 0)
 	    : windowskin(0),
-	      windowskinWatch(this, windowskin),
+	      windowskinWatch(*this, windowskin),
 	      contents(0),
-	      contentsWatch(this, contents, &WindowPrivate::markControlVertDirty),
+	      contentsWatch(*this, contents, &WindowPrivate::markControlVertDirty),
 	      bgStretch(true),
 	      cursorRect(&tmp.rect),
 	      active(true),