diff --git a/layout/xul/base/src/nsSprocketLayout.cpp b/layout/xul/base/src/nsSprocketLayout.cpp
index b6803f994d4e..6d78f8fa4bd0 100644
--- a/layout/xul/base/src/nsSprocketLayout.cpp
+++ b/layout/xul/base/src/nsSprocketLayout.cpp
@@ -782,8 +782,10 @@ nsSprocketLayout::PopulateBoxSizes(nsIBox* aBox, nsBoxLayoutState& aState, nsBox
 
   while(child)
   {
-    while (currentBox && currentBox->bogus)
+    while (currentBox && currentBox->bogus) {
+      last = currentBox;
       currentBox = currentBox->next;
+    }
     ++childCount;
     nsSize pref(0,0);
     nsSize min(0,0);