diff --git a/xpfe/components/shistory/src/nsSHEntry.h b/xpfe/components/shistory/src/nsSHEntry.h
index 6a9dc73ee4a..ef49e23597a 100644
--- a/xpfe/components/shistory/src/nsSHEntry.h
+++ b/xpfe/components/shistory/src/nsSHEntry.h
@@ -64,8 +64,8 @@ private:
 	nsVoidArray                     mChildren;
 	PRUint32                        mLoadType;  
 	PRUint32                        mID;
-  PRBool                          mIsFrameNavigation;
-  PRBool                          mSaveLayoutState;
+  PRPackedBool                    mIsFrameNavigation;
+  PRPackedBool                    mSaveLayoutState;
   PRPackedBool                    mExpired;
   nsCOMPtr<nsISupports>           mCacheKey;
   nsISHEntry *                    mParent;  // weak reference