Index: bp-themes/bp-default/members/single/member-header.php
===================================================================
--- bp-themes/bp-default/members/single/member-header.php	(revision 7231)
+++ bp-themes/bp-default/members/single/member-header.php	(working copy)
@@ -25,7 +25,7 @@
 		<a href="<?php bp_displayed_user_link(); ?>"><?php bp_displayed_user_fullname(); ?></a>
 	</h2>
 
-	<span class="user-nicename">@<?php bp_displayed_user_username(); ?></span>
+	<?php bp_displayed_user_mention_username();?>
 	<span class="activity"><?php bp_last_activity( bp_displayed_user_id() ); ?></span>
 
 	<?php do_action( 'bp_before_member_header_meta' ); ?>
Index: bp-members/bp-members-template.php
===================================================================
--- bp-members/bp-members-template.php	(revision 7231)
+++ bp-members/bp-members-template.php	(working copy)
@@ -936,6 +936,39 @@
 		return apply_filters( 'bp_get_loggedin_user_fullname', isset( $bp->loggedin_user->fullname ) ? $bp->loggedin_user->fullname : '' );
 	}
 
+/**
+ * Displays the @username
+ *
+ * @uses bp_get_displayed_user_mention_username() to get the @username
+ */	
+function bp_displayed_user_mention_username() {
+	echo bp_get_displayed_user_mention_username();
+}
+
+	/**
+	 * Checks if activity mentions are enable before displaying the @username in member's header
+	 *
+	 * @uses bp_activity_do_mentions() to check if activity mentions are enable
+	 * @uses get_post_type() to determine whether Theme Compat is used or not
+	 * @uses bp_get_displayed_user_username() to get the username
+	 * @return string html for @username
+	 */
+	function bp_get_displayed_user_mention_username() {
+
+		if( !bp_activity_do_mentions() )
+			return;
+
+		$output = false;
+
+		if( 'bp_members' == get_post_type() )
+			$output = '<h2 class="user-nicename">@' . bp_get_displayed_user_username() .'</h2>';
+
+		else
+			$output = '<span class="user-nicename">@' . bp_get_displayed_user_username() .'</span>';
+
+		return apply_filters( 'bp_get_displayed_user_mention_username', $output );
+	}
+
 function bp_displayed_user_username() {
 	echo bp_get_displayed_user_username();
 }
Index: bp-templates/bp-legacy/buddypress/members/single/member-header.php
===================================================================
--- bp-templates/bp-legacy/buddypress/members/single/member-header.php	(revision 7231)
+++ bp-templates/bp-legacy/buddypress/members/single/member-header.php	(working copy)
@@ -21,7 +21,7 @@
 
 <div id="item-header-content">
 
-	<h2 class="user-nicename">@<?php bp_displayed_user_username(); ?></h2>
+	<?php bp_displayed_user_mention_username();?>
 	<span class="activity"><?php bp_last_activity( bp_displayed_user_id() ); ?></span>
 
 	<?php do_action( 'bp_before_member_header_meta' ); ?>