diff --git a/base/src/main/java/de/staropensource/sosengine/base/annotations/EventListener.java b/base/src/main/java/de/staropensource/sosengine/base/annotations/EventListener.java
index 07a1e1b0..fce6eb90 100644
--- a/base/src/main/java/de/staropensource/sosengine/base/annotations/EventListener.java
+++ b/base/src/main/java/de/staropensource/sosengine/base/annotations/EventListener.java
@@ -21,6 +21,7 @@ package de.staropensource.sosengine.base.annotations;
 
 import de.staropensource.sosengine.base.classes.Event;
 import de.staropensource.sosengine.base.classes.EventPriority;
+import org.jetbrains.annotations.NotNull;
 
 import java.lang.annotation.*;
 
@@ -37,6 +38,7 @@ public @interface EventListener {
      *
      * @return the event the method listens for
      */
+    @NotNull
     Class<? extends Event> event();
 
     /**
@@ -44,5 +46,6 @@ public @interface EventListener {
      *
      * @return the event priority
      */
-    EventPriority priority();
+    @NotNull
+    EventPriority priority() default EventPriority.DEFAULT;
 }