diff --git a/src/plugins/BasePlugin.php b/src/plugins/BasePlugin.php
index 2f61a39..53da79a 100644
--- a/src/plugins/BasePlugin.php
+++ b/src/plugins/BasePlugin.php
@@ -14,7 +14,7 @@ class BasePlugin implements Plugin
     /**
      * {@inheritdoc}
      */
-    public function prepareRequest(array $jobs, array $originalJobs)
+    public function prepareRequest(array $jobs, array $originalJobs) : array
     {
         return $jobs;
     }
diff --git a/src/plugins/Plugin.php b/src/plugins/Plugin.php
index 6cfe4a5..aac80a5 100644
--- a/src/plugins/Plugin.php
+++ b/src/plugins/Plugin.php
@@ -24,7 +24,7 @@ public function getViewData($name, array $data);
      * @param \WF\Hypernova\Job[]   $originalJobs
      * @return \WF\Hypernova\Job
      */
-    public function prepareRequest(array $jobs, array $originalJobs);
+    public function prepareRequest(array $jobs, array $originalJobs) : array;
 
     /**
      * @param \WF\Hypernova\Job[] $jobs