diff --git a/src/Plan/DefaultIntervalGenerator.php b/src/Plan/DefaultIntervalGenerator.php
index 9585813f..37ed1d2b 100644
--- a/src/Plan/DefaultIntervalGenerator.php
+++ b/src/Plan/DefaultIntervalGenerator.php
@@ -36,6 +36,13 @@ public function getEndOfNextSubscriptionCycle(Subscription $subscription = null)
         return $cycle_ends_at->modify('+'.$this->interval);
     }
 
+    /**
+     * @return string
+     */
+    public function interval() {
+        return $this->interval;
+    }
+
     /**
      * @return bool
      */