diff --git a/mozilla/gfx/src/xlib/nsImageXlib.cpp b/mozilla/gfx/src/xlib/nsImageXlib.cpp
index 138d21b8d20..c4af4067193 100644
--- a/mozilla/gfx/src/xlib/nsImageXlib.cpp
+++ b/mozilla/gfx/src/xlib/nsImageXlib.cpp
@@ -412,7 +412,7 @@ void nsImageXlib::UpdateCachedImage()
                      XLIB_RGB_DITHER_MAX,
                      mImageBits + mRowBytes * rect->y + 3 * rect->x,
                      mRowBytes,
-                     aUpdateRect->x, aUpdateRect->y);
+                     rect->x, rect->y);
     }
   }