diff --git a/src/Demos/osgprerender/osgprerender.cpp b/src/Demos/osgprerender/osgprerender.cpp
index fc5a98792..38957ad5c 100644
--- a/src/Demos/osgprerender/osgprerender.cpp
+++ b/src/Demos/osgprerender/osgprerender.cpp
@@ -292,6 +292,8 @@ class MyTextureSubloadCallback : public osg::Texture2D::SubloadCallback
     
         MyTextureSubloadCallback():
             _subloadMode(AUTO),
+            _textureWidth(0),
+            _textureHeight(0),
             _subloadTextureOffsetX(0),
             _subloadTextureOffsetY(0),
             _subloadImageOffsetX(0),