diff --git a/source/org/jivesoftware/smack/Roster.java b/source/org/jivesoftware/smack/Roster.java
index 6b2fc3567..4a4ffdd95 100644
--- a/source/org/jivesoftware/smack/Roster.java
+++ b/source/org/jivesoftware/smack/Roster.java
@@ -519,8 +519,8 @@ public class Roster implements ConnectionListener {
      * @param updatedEntries the collection of address of the updated contacts.
      * @param deletedEntries the collection of address of the deleted contacts.
      */
-    private void fireRosterChangedEvent(Collection addedEntries, Collection updatedEntries,
-            Collection deletedEntries)
+    private void fireRosterChangedEvent(Collection<String> addedEntries, Collection<String> updatedEntries,
+            Collection<String> deletedEntries)
     {
         for (RosterListener listener : rosterListeners) {
             if (!addedEntries.isEmpty()) {
diff --git a/source/org/jivesoftware/smack/RosterListener.java b/source/org/jivesoftware/smack/RosterListener.java
index 11f6bcdd3..71caa143c 100644
--- a/source/org/jivesoftware/smack/RosterListener.java
+++ b/source/org/jivesoftware/smack/RosterListener.java
@@ -36,21 +36,21 @@ public interface RosterListener {
      *
      * @param addresses the XMPP addresses of the contacts that have been added to the roster.
      */
-    public void entriesAdded(Collection addresses);
+    public void entriesAdded(Collection<String> addresses);
 
     /**
      * Called when a roster entries are updated.
      *
      * @param addresses the XMPP addresses of the contacts whose entries have been updated.
      */
-    public void entriesUpdated(Collection addresses);
+    public void entriesUpdated(Collection<String> addresses);
 
     /**
      * Called when a roster entries are removed.
      *
      * @param addresses the XMPP addresses of the contacts that have been removed from the roster.
      */
-    public void entriesDeleted(Collection addresses);
+    public void entriesDeleted(Collection<String> addresses);
 
     /**
      * Called when the presence of a roster entry is changed.