diff --git a/src/main/java/com/cloudbees/jenkins/GitHubPushTrigger.java b/src/main/java/com/cloudbees/jenkins/GitHubPushTrigger.java
index 6ed87c3ec..7cdd9a5e3 100644
--- a/src/main/java/com/cloudbees/jenkins/GitHubPushTrigger.java
+++ b/src/main/java/com/cloudbees/jenkins/GitHubPushTrigger.java
@@ -119,7 +119,10 @@ public void onPost(final GitHubTriggerEvent event) {
                 }
             }
 
-            String lowercaseTriggeredByUser = event.getTriggeredByUser() != null? event.getTriggeredByUser().toLowerCase(): null;
+            String lowercaseTriggeredByUser = null;
+            if (event.getTriggeredByUser() != null) {
+                lowercaseTriggeredByUser = event.getTriggeredByUser().toLowerCase();
+            }
             if (lowercaseExcludedUsers != null && lowercaseExcludedUsers.contains(lowercaseTriggeredByUser)) {
                 return; // user is excluded from triggering build
             }