diff --git a/Source/WebCore/ChangeLog b/Source/WebCore/ChangeLog
index 4e1159cd3a9e..94d52a683cf9 100644
--- a/Source/WebCore/ChangeLog
+++ b/Source/WebCore/ChangeLog
@@ -1,3 +1,27 @@
+2015-07-05  Chris Dumez  <cdumez@apple.com>
+
+        [WK2] WebBackForwardListItems' pageState is not kept up-to-date
+        https://bugs.webkit.org/show_bug.cgi?id=146614
+        <rdar://problem/21585268>
+
+        Reviewed by Gavin Barraclough.
+
+        WebBackForwardListItems' pageState on UIProcess-side were not kept
+        up-to-date when it was updated on WebContent process side. This meant
+        that we were losing the scroll position (among other things) when
+        transferring the session state over from one view to another.
+
+        We now call notifyHistoryItemChanged(item) after saving the scroll
+        position and the view state on the HistoryItem. As a result, the
+        WebBackForwardListProxy will send the updated pageState to the
+        UIProcess.
+
+        * history/HistoryItem.cpp:
+        (WebCore::HistoryItem::notifyChanged):
+        * history/HistoryItem.h:
+        * loader/HistoryController.cpp:
+        (WebCore::HistoryController::saveScrollPositionAndViewStateToItem):
+
 2015-07-03  Chris Dumez  <cdumez@apple.com>
 
         REGRESSION (r178097): HTMLSelectElement.add(option, undefined) prepends option to the list of options; should append to the end of the list of options
diff --git a/Source/WebCore/history/HistoryItem.cpp b/Source/WebCore/history/HistoryItem.cpp
index 229bab8e7a23..3fa631f7dba6 100644
--- a/Source/WebCore/history/HistoryItem.cpp
+++ b/Source/WebCore/history/HistoryItem.cpp
@@ -571,6 +571,11 @@ void HistoryItem::setRedirectURLs(std::unique_ptr<Vector<String>> redirectURLs)
     m_redirectURLs = WTF::move(redirectURLs);
 }
 
+void HistoryItem::notifyChanged()
+{
+    notifyHistoryItemChanged(this);
+}
+
 #ifndef NDEBUG
 
 int HistoryItem::showTree() const
diff --git a/Source/WebCore/history/HistoryItem.h b/Source/WebCore/history/HistoryItem.h
index 4d843c48f2f5..b3f6ba5e6b31 100644
--- a/Source/WebCore/history/HistoryItem.h
+++ b/Source/WebCore/history/HistoryItem.h
@@ -206,6 +206,8 @@ class HistoryItem : public RefCounted<HistoryItem> {
     void setSharedLinkUniqueIdentifier(const String& sharedLinkUniqueidentifier) { m_sharedLinkUniqueIdentifier = sharedLinkUniqueidentifier; }
 #endif
 
+    void notifyChanged();
+
 private:
     WEBCORE_EXPORT HistoryItem();
     WEBCORE_EXPORT HistoryItem(const String& urlString, const String& title);
diff --git a/Source/WebCore/loader/HistoryController.cpp b/Source/WebCore/loader/HistoryController.cpp
index d4610cae9274..fcdfc24f6678 100644
--- a/Source/WebCore/loader/HistoryController.cpp
+++ b/Source/WebCore/loader/HistoryController.cpp
@@ -90,6 +90,9 @@ void HistoryController::saveScrollPositionAndViewStateToItem(HistoryItem* item)
 
     // FIXME: It would be great to work out a way to put this code in WebCore instead of calling through to the client.
     m_frame.loader().client().saveViewStateToItem(item);
+
+    // Notify clients that the HistoryItem has changed.
+    item->notifyChanged();
 }
 
 void HistoryController::clearScrollPositionAndViewState()