--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -5825,22 +5825,24 @@ nsContentUtils::GetUTFOrigin(nsIURI* aUR
   NS_PRECONDITION(aURI, "missing uri");
 
   // For Blob URI we have to return the origin of page using its principal.
   nsCOMPtr<nsIURIWithPrincipal> uriWithPrincipal = do_QueryInterface(aURI);
   if (uriWithPrincipal) {
     nsCOMPtr<nsIPrincipal> principal;
     uriWithPrincipal->GetPrincipal(getter_AddRefs(principal));
 
-    nsCOMPtr<nsIURI> uri;
-    nsresult rv = principal->GetURI(getter_AddRefs(uri));
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    if (uri && uri != aURI) {
-      return GetUTFOrigin(uri, aOrigin);
+    if (principal) {
+      nsCOMPtr<nsIURI> uri;
+      nsresult rv = principal->GetURI(getter_AddRefs(uri));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      if (uri && uri != aURI) {
+        return GetUTFOrigin(uri, aOrigin);
+      }
     }
   }
 
   aOrigin.Truncate();
 
   nsCOMPtr<nsIURI> uri = NS_GetInnermostURI(aURI);
   NS_ENSURE_TRUE(uri, NS_ERROR_UNEXPECTED);