diff --git a/phpBB/phpbb/textformatter/s9e/mention_helper.php b/phpBB/phpbb/textformatter/s9e/mention_helper.php
index c693151f1f..fded9c5cd4 100644
--- a/phpBB/phpbb/textformatter/s9e/mention_helper.php
+++ b/phpBB/phpbb/textformatter/s9e/mention_helper.php
@@ -13,7 +13,7 @@
 
 namespace phpbb\textformatter\s9e;
 
-use s9e\TextFormatter\Utils;
+use s9e\TextFormatter\Utils as TextFormatterUtils;
 
 class mention_helper
 {
@@ -117,11 +117,11 @@ class mention_helper
 
 		// TODO: think about optimization for caching colors.
 		$this->get_colors(
-			Utils::getAttributeValues($xml, 'MENTION', 'user_id'),
-			Utils::getAttributeValues($xml, 'MENTION', 'group_id')
+			TextFormatterUtils::getAttributeValues($xml, 'MENTION', 'user_id'),
+			TextFormatterUtils::getAttributeValues($xml, 'MENTION', 'group_id')
 		);
 
-		return Utils::replaceAttributes(
+		return TextFormatterUtils::replaceAttributes(
 			$xml,
 			'MENTION',
 			function ($attributes) use ($user_profile_url, $group_profile_url)
diff --git a/tests/notification/fixtures/services_notification.yml b/tests/notification/fixtures/services_notification.yml
index 470768d986..69e6374f4c 100644
--- a/tests/notification/fixtures/services_notification.yml
+++ b/tests/notification/fixtures/services_notification.yml
@@ -44,6 +44,9 @@ services:
     text_formatter.s9e.quote_helper:
         synthetic: true
 
+    text_formatter.s9e.mention_helper:
+        synthetic: true
+
     text_formatter.parser:
         synthetic: true