diff --git a/phpBB/viewtopic.php b/phpBB/viewtopic.php
index ebdb54fe8d..cd0dae2b46 100644
--- a/phpBB/viewtopic.php
+++ b/phpBB/viewtopic.php
@@ -1143,7 +1143,10 @@ $db->sql_freeresult($result);
 // Load custom profile fields
 if ($config['load_cpf_viewtopic'])
 {
-	include($phpbb_root_path . 'includes/functions_profile_fields.' . $phpEx);
+	if (!class_exists('custom_profile'))
+	{
+		include($phpbb_root_path . 'includes/functions_profile_fields.' . $phpEx);
+	}
 	$cp = new custom_profile();
 
 	// Grab all profile fields from users in id cache for later use - similar to the poster cache