--- a/layout/generic/nsFlexContainerFrame.h
+++ b/layout/generic/nsFlexContainerFrame.h
@@ -325,17 +325,14 @@ protected:
    *                           reflow methods to interpret positions correctly).
    */
   void ReflowPlaceholders(nsPresContext* aPresContext,
                           const ReflowInput& aReflowInput,
                           nsTArray<nsIFrame*>& aPlaceholders,
                           const mozilla::LogicalPoint& aContentBoxOrigin,
                           const nsSize& aContainerSize);
 
-  bool mChildrenHaveBeenReordered; // Have we ever had to reorder our kids
-                                   // to satisfy their 'order' values?
-
   nscoord mBaselineFromLastReflow;
   // Note: the last baseline is a distance from our border-box end edge.
   nscoord mLastBaselineFromLastReflow;
 };
 
 #endif /* nsFlexContainerFrame_h___ */