--- a/browser/components/about/AboutRedirector.cpp
+++ b/browser/components/about/AboutRedirector.cpp
@@ -79,17 +79,17 @@ static const RedirEntry kRedirMap[] = {
     nsIAboutModule::HIDE_FROM_ABOUTABOUT },
   { "sessionrestore", "chrome://browser/content/aboutSessionRestore.xhtml",
     nsIAboutModule::ALLOW_SCRIPT |
     nsIAboutModule::HIDE_FROM_ABOUTABOUT },
   { "welcomeback", "chrome://browser/content/aboutWelcomeBack.xhtml",
     nsIAboutModule::ALLOW_SCRIPT |
     nsIAboutModule::HIDE_FROM_ABOUTABOUT },
   // Actual activity stream URL for home and newtab are set in channel creation
-  { "home", "about:blank", ACTIVITY_STREAM_FLAGS | nsIAboutModule::MAKE_LINKABLE }, // Bug 1438367 to try removing MAKE_LINKABLE again
+  { "home", "about:blank", ACTIVITY_STREAM_FLAGS },
   { "newtab", "about:blank", ACTIVITY_STREAM_FLAGS },
   { "welcome", "about:blank",
     nsIAboutModule::URI_MUST_LOAD_IN_CHILD |
     nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT |
     nsIAboutModule::ALLOW_SCRIPT },
   { "library", "chrome://browser/content/aboutLibrary.xhtml",
     nsIAboutModule::URI_MUST_LOAD_IN_CHILD |
     nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT },

--- a/caps/ContentPrincipal.cpp
+++ b/caps/ContentPrincipal.cpp
@@ -415,16 +415,24 @@ ContentPrincipal::Read(nsIObjectInputStr
   nsCOMPtr<nsISupports> supports;
   nsCOMPtr<nsIURI> codebase;
   nsresult rv = NS_ReadOptionalObject(aStream, true, getter_AddRefs(supports));
   if (NS_FAILED(rv)) {
     return rv;
   }
 
   codebase = do_QueryInterface(supports);
+  // Enforce re-parsing about: URIs so that if they change, we continue to use
+  // their new principals correctly.
+  bool isAbout = false;
+  if (NS_SUCCEEDED(codebase->SchemeIs("about", &isAbout)) && isAbout) {
+    nsAutoCString spec;
+    codebase->GetSpec(spec);
+    NS_ENSURE_SUCCESS(NS_NewURI(getter_AddRefs(codebase), spec), NS_ERROR_FAILURE);
+  }
 
   nsCOMPtr<nsIURI> domain;
   rv = NS_ReadOptionalObject(aStream, true, getter_AddRefs(supports));
   if (NS_FAILED(rv)) {
     return rv;
   }
 
   domain = do_QueryInterface(supports);