diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/avatar/element/DataExtension.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/avatar/element/DataExtension.java
index 4dbb8e095..5456a8fda 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/avatar/element/DataExtension.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/avatar/element/DataExtension.java
@@ -91,7 +91,7 @@ public class DataExtension implements ExtensionElement {
     }
 
     @Override
-    public CharSequence toXML(XmlEnvironment xmlEnvironment) {
+    public XmlStringBuilder toXML(XmlEnvironment xmlEnvironment) {
         XmlStringBuilder xml = new XmlStringBuilder(this, xmlEnvironment);
         xml.rightAngleBracket();
         xml.escape(this.getDataAsString());
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/avatar/element/MetadataExtension.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/avatar/element/MetadataExtension.java
index 29aa943a3..8d7a6a764 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/avatar/element/MetadataExtension.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/avatar/element/MetadataExtension.java
@@ -101,7 +101,7 @@ public class MetadataExtension implements ExtensionElement {
     }
 
     @Override
-    public CharSequence toXML(XmlEnvironment xmlEnvironment) {
+    public XmlStringBuilder toXML(XmlEnvironment xmlEnvironment) {
         XmlStringBuilder xml = new XmlStringBuilder(this, xmlEnvironment);
         appendInfoElements(xml);
         appendPointerElements(xml);