diff --git a/layout/xul/base/src/grid/nsGridRowGroupLayout.h b/layout/xul/base/src/grid/nsGridRowGroupLayout.h
index 106c92ec6117..77a98b0fb525 100644
--- a/layout/xul/base/src/grid/nsGridRowGroupLayout.h
+++ b/layout/xul/base/src/grid/nsGridRowGroupLayout.h
@@ -44,7 +44,6 @@ protected:
   static void AddWidth(nsSize& aSize, nscoord aSize2, bool aIsHorizontal);
 
 private:
-  nsGridRow* mRowColumn;
   int32_t mRowCount;
 };