diff --git a/layout/generic/nsHTMLFrame.cpp b/layout/generic/nsHTMLFrame.cpp
index c41d9d672961..f01a2a03ada3 100644
--- a/layout/generic/nsHTMLFrame.cpp
+++ b/layout/generic/nsHTMLFrame.cpp
@@ -571,6 +571,13 @@ CanvasFrame::Reflow(nsPresContext*          aPresContext,
                                      nsSize(aReflowState.availableWidth,
                                             NS_UNCONSTRAINEDSIZE));
 
+    if (aReflowState.mFlags.mVResize &&
+        (kidFrame->GetStateBits() & NS_FRAME_CONTAINS_RELATIVE_HEIGHT)) {
+      // Tell our kid it's being vertically resized too.  Bit of a
+      // hack for framesets.
+      kidReflowState.mFlags.mVResize = PR_TRUE;
+    }
+    
     // Reflow the frame
     ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowState,
                 kidReflowState.mComputedMargin.left, kidReflowState.mComputedMargin.top,