diff --git a/browser/components/sessionstore/src/SessionStorage.jsm b/browser/components/sessionstore/src/SessionStorage.jsm
index 501a4d827c71..daca9c948792 100644
--- a/browser/components/sessionstore/src/SessionStorage.jsm
+++ b/browser/components/sessionstore/src/SessionStorage.jsm
@@ -18,8 +18,7 @@ XPCOMUtils.defineLazyModuleGetter(this, "console",
 // Returns the principal for a given |frame| contained in a given |docShell|.
 function getPrincipalForFrame(docShell, frame) {
   let ssm = Services.scriptSecurityManager;
-  let doc = frame && frame.document;
-  let uri = Services.io.newURI(doc.documentURI, null, null);
+  let uri = frame.document.documentURIObject;
   return ssm.getDocShellCodebasePrincipal(uri, docShell);
 }
 
diff --git a/browser/components/sessionstore/test/browser_broadcast.js b/browser/components/sessionstore/test/browser_broadcast.js
index 9cd7ad97bb04..8e3bda450451 100644
--- a/browser/components/sessionstore/test/browser_broadcast.js
+++ b/browser/components/sessionstore/test/browser_broadcast.js
@@ -59,12 +59,12 @@ add_task(function flush_on_duplicate() {
     "sessionStorage data has been flushed when duplicating tabs");
 
   yield promiseTabRestored(tab2);
-  let {storage} = JSON.parse(ss.getTabState(tab2));
+  gBrowser.removeTab(tab2)
+  let [{state: {storage}}] = JSON.parse(ss.getClosedTabData(window));
   is(storage["http://example.com"].test, "on-duplicate",
     "sessionStorage data has been flushed when duplicating tabs");
 
   gBrowser.removeTab(tab);
-  gBrowser.removeTab(tab2);
 });
 
 /**