diff --git a/src/main/java/cc/carm/lib/easylistener/EasyListener.java b/src/main/java/cc/carm/lib/easylistener/EasyListener.java
index 45a971d..2ff9b79 100644
--- a/src/main/java/cc/carm/lib/easylistener/EasyListener.java
+++ b/src/main/java/cc/carm/lib/easylistener/EasyListener.java
@@ -136,7 +136,9 @@ public class EasyListener implements Listener {
                                                  @Nullable EventPriority priority,
                                                  @Nullable Predicate<? super T> eventPredicate,
                                                  @Nullable Consumer<? super T> afterCancelled) {
-        requireType(Cancellable.class, eventClass, "Event class " + eventClass.getName() + " is not cancellable");
+        if (!Cancellable.class.isAssignableFrom(eventClass)) {
+            throw new IllegalArgumentException("Event class " + eventClass.getName() + " is not cancellable");
+        }
 
         final Predicate<? super T> predicate = Optional.ofNullable(eventPredicate).orElse(t -> true);
         return handle(eventClass, priority, true, (event) -> {
@@ -274,13 +276,6 @@ public class EasyListener implements Listener {
         };
     }
 
-    protected void requireType(@NotNull Class<?> target, @NotNull Class<?> value,
-                               @Nullable String message) throws IllegalArgumentException {
-        if (target.isAssignableFrom(value)) return;
-        if (message == null) throw new IllegalArgumentException();
-        else throw new IllegalArgumentException(message);
-    }
-
     protected void register(@NotNull Class<? extends Event> eventClass, @NotNull RegisteredListener listener) {
         getEventListeners(eventClass).register(listener);
     }