diff --git a/dom/base/nsGlobalWindowOuter.cpp b/dom/base/nsGlobalWindowOuter.cpp
index 956bb7bc6cea..bf9a86a1c54f 100644
--- a/dom/base/nsGlobalWindowOuter.cpp
+++ b/dom/base/nsGlobalWindowOuter.cpp
@@ -5145,7 +5145,7 @@ void nsGlobalWindowOuter::NotifyContentBlockingState(unsigned aState,
     return;
   }
 
-  eventSink->OnSecurityChange(aChannel, state);
+  eventSink->OnContentBlockingEvent(aChannel, state);
 }
 
 // static
diff --git a/netwerk/base/nsISecurityEventSink.idl b/netwerk/base/nsISecurityEventSink.idl
index d824fe5a7f0b..fdefded1e79c 100644
--- a/netwerk/base/nsISecurityEventSink.idl
+++ b/netwerk/base/nsISecurityEventSink.idl
@@ -19,6 +19,15 @@ interface nsISecurityEventSink : nsISupports
       */
 
     void onSecurityChange(in nsISupports i_Context, in unsigned long state);
+
+    /**
+      * Fired when a content blocking event occurs during the time
+      * when a document is alive.  This interface should be called
+      * by Gecko to notify nsIWebProgressListeners that there is a
+      * new content blocking event.  Content blocking events are in
+      * nsIWebProgressListeners.idl.
+      */
+    void onContentBlockingEvent(in nsISupports i_Context, in unsigned long event);
 };
 
 
diff --git a/uriloader/base/nsDocLoader.cpp b/uriloader/base/nsDocLoader.cpp
index 28a5150259fc..40e87c23f20c 100644
--- a/uriloader/base/nsDocLoader.cpp
+++ b/uriloader/base/nsDocLoader.cpp
@@ -1412,6 +1412,25 @@ NS_IMETHODIMP nsDocLoader::OnSecurityChange(nsISupports* aContext,
   return NS_OK;
 }
 
+NS_IMETHODIMP nsDocLoader::OnContentBlockingEvent(nsISupports* aContext,
+                                                  uint32_t aEvent) {
+  //
+  // Fire progress notifications out to any registered nsIWebProgressListeners.
+  //
+
+  nsCOMPtr<nsIRequest> request = do_QueryInterface(aContext);
+  nsIWebProgress* webProgress = static_cast<nsIWebProgress*>(this);
+
+  NOTIFY_LISTENERS(nsIWebProgress::NOTIFY_SECURITY,
+                   listener->OnSecurityChange(webProgress, request, aEvent););
+
+  // Pass the notification up to the parent...
+  if (mParent) {
+    mParent->OnContentBlockingEvent(aContext, aEvent);
+  }
+  return NS_OK;
+}
+
 /*
  * Implementation of nsISupportsPriority methods...
  *