diff --git a/core/src/main/java/org/ogcs/event/EventListenerSet.java b/core/src/main/java/org/ogcs/event/EventListenerSet.java
index bb37e89..e91e06b 100644
--- a/core/src/main/java/org/ogcs/event/EventListenerSet.java
+++ b/core/src/main/java/org/ogcs/event/EventListenerSet.java
@@ -20,7 +20,7 @@
 import java.util.Set;
 
 /**
- *
+ * The {@link EventListener} collection.
  * @author TinyZ.
  * @since 1.0
  */
@@ -50,6 +50,10 @@ public EventListener[] listeners() {
         return listeners.toArray(new EventListener[listeners.size()]);
     }
 
+    public boolean isEmpty() {
+        return listeners.isEmpty();
+    }
+
     public int size() {
         return listeners.size();
     }
diff --git a/core/src/main/java/org/ogcs/event/MultiListenerEventDispatcher.java b/core/src/main/java/org/ogcs/event/MultiListenerEventDispatcher.java
index 63ab0bd..b124c16 100644
--- a/core/src/main/java/org/ogcs/event/MultiListenerEventDispatcher.java
+++ b/core/src/main/java/org/ogcs/event/MultiListenerEventDispatcher.java
@@ -97,7 +97,11 @@ public void removeEventListener(Object type, EventListener listener) {
             return;
         }
         if (listeners instanceof EventListenerSet) {
-            ((EventListenerSet) listeners).remove(listener);
+            EventListenerSet set = (EventListenerSet) listeners;
+            set.remove(listener);
+            if (set.isEmpty()) {
+                map.remove(type);
+            }
         } else if (listeners.equals(listener)) {
             map.remove(type);
         }