diff --git a/core/lib/Drupal/Core/Routing/MatcherDumper.php b/core/lib/Drupal/Core/Routing/MatcherDumper.php
index f129f02..93f9ae2 100644
--- a/core/lib/Drupal/Core/Routing/MatcherDumper.php
+++ b/core/lib/Drupal/Core/Routing/MatcherDumper.php
@@ -118,7 +118,8 @@ public function dump(array $options = array()) {
     // Delete any old records in this route set first, then insert the new ones.
     // That avoids stale data. The transaction makes it atomic to avoid
     // unstable router states due to random failures.
- 
+
+    $transaction = $this->connection->startTransaction();
     try {
       $this->connection->delete($this->tableName)
         ->condition('route_set', $options['route_set'])
@@ -128,8 +129,7 @@ public function dump(array $options = array()) {
       // the queued routes.
       $this->routes = NULL;
     } catch (\Exception $e) {
-      $txn = $this->connection->startTransaction();
-      $txn->rollback();
+      $transaction->rollback();
       watchdog_exception('Routing', $e);
       throw $e;
     }