diff --git a/phpBB/includes/acp/acp_attachments.php b/phpBB/includes/acp/acp_attachments.php
index 5557ecc835..274aa97122 100644
--- a/phpBB/includes/acp/acp_attachments.php
+++ b/phpBB/includes/acp/acp_attachments.php
@@ -1239,13 +1239,17 @@ class acp_attachments
 					$display_cat = isset($extensions[$row['extension']]['display_cat']) ? $extensions[$row['extension']]['display_cat'] : ATTACHMENT_CATEGORY_NONE;
 					$l_downloaded_viewed = ($display_cat == ATTACHMENT_CATEGORY_NONE) ? 'DOWNLOAD_COUNTS' : 'VIEWED_COUNTS';
 
+					// Capitalises the group name and checks if its key exists in the language file
+					$up_group_name = utf8_strtoupper($extensions[$row['extension']]['group_name']);
+					$ext_group_name = (!empty($up_group_name)) ? (isset($user->lang['EXT_GROUP_' .  $up_group_name]) ? $user->lang['EXT_GROUP_' .  $up_group_name] : '') : '';
+
 					$template->assign_block_vars('attachments', array(
 						'ATTACHMENT_POSTER'	=> get_username_string('full', (int) $row['poster_id'], (string) $row['username'], (string) $row['user_colour'], (string) $row['username']),
 						'FILESIZE'			=> get_formatted_filesize((int) $row['filesize']),
 						'FILETIME'			=> $user->format_date((int) $row['filetime']),
 						'REAL_FILENAME'		=> (!$row['in_message']) ? utf8_basename((string) $row['real_filename']) : '',
 						'PHYSICAL_FILENAME'	=> utf8_basename((string) $row['physical_filename']),
-						'EXT_GROUP_NAME'	=> (!empty($extensions[$row['extension']]['group_name'])) ? $user->lang['EXT_GROUP_' . $extensions[$row['extension']]['group_name']] : '',
+						'EXT_GROUP_NAME'	=> $ext_group_name,
 						'COMMENT'			=> $comment,
 						'TOPIC_TITLE'		=> (!$row['in_message']) ? (string) $row['topic_title'] : '',
 						'ATTACH_ID'			=> (int) $row['attach_id'],