diff --git a/src/main/java/org/cp/elements/util/sort/annotation/Sortable.java b/src/main/java/org/cp/elements/util/sort/annotation/Sortable.java
index <HASH>..<HASH> 100644
--- a/src/main/java/org/cp/elements/util/sort/annotation/Sortable.java
+++ b/src/main/java/org/cp/elements/util/sort/annotation/Sortable.java
@@ -68,6 +68,6 @@ public @interface Sortable {
    * @see java.lang.Class
    * @see java.util.Comparator
    */
-  public Class<Comparator> orderBy() default Comparator.class;
+  public Class<? extends Comparator> orderBy() default Comparator.class;
 
 }
Changed the return type on the orderBy attribute of the @Sortable annotation to Class<? extends Comparator>.