diff --git a/app/controllers/api/proxy.php b/app/controllers/api/proxy.php
index c3a9fbe3ee..eb913dbb63 100644
--- a/app/controllers/api/proxy.php
+++ b/app/controllers/api/proxy.php
@@ -49,7 +49,7 @@ App::post('/v1/proxy/rules')
         }
 
         $functionsDomain = App::getEnv('_APP_DOMAIN_FUNCTIONS', '');
-        if (str_ends_with($functionsDomain, $domain)) {
+        if (str_ends_with($domain, $functionsDomain)) {
             throw new Exception(Exception::GENERAL_ARGUMENT_INVALID, 'You cannot assign your functions domain or it\'s subdomain to specific resource. Please use different domain.');
         }