diff --git a/src/main/java/com/bitplaces/rundeck/plugins/slack/SlackNotificationPlugin.java b/src/main/java/com/bitplaces/rundeck/plugins/slack/SlackNotificationPlugin.java
index 37ae461..5e09a6c 100644
--- a/src/main/java/com/bitplaces/rundeck/plugins/slack/SlackNotificationPlugin.java
+++ b/src/main/java/com/bitplaces/rundeck/plugins/slack/SlackNotificationPlugin.java
@@ -63,7 +63,7 @@ public class SlackNotificationPlugin implements NotificationPlugin {
 
     private static final Configuration FREEMARKER_CFG = new Configuration();
 
-    @PluginProperty(title = "WebHook URL", description = "Slack Incoming WebHook URL", scope = PropertyScope.Framework)
+    @PluginProperty(title = "WebHook URL", description = "Slack Incoming WebHook URL", required = true)
     private String webhook_url;
 
     /**