diff --git a/src/main/java/org/apache/commons/lang3/mutable/Mutable.java b/src/main/java/org/apache/commons/lang3/mutable/Mutable.java
index 0773c405b..ac21cd059 100644
--- a/src/main/java/org/apache/commons/lang3/mutable/Mutable.java
+++ b/src/main/java/org/apache/commons/lang3/mutable/Mutable.java
@@ -27,6 +27,7 @@
  * a collection (for example a total in a map) without needing to create new Integer/Long wrapper objects.
  * 
  * @since 2.1
+ * @param <T> the type to set and get 
  * @version $Id$
  */
 public interface Mutable<T> {