diff --git a/lib/kamal/configuration/accessory.rb b/lib/kamal/configuration/accessory.rb
index 50f70e58..1317501e 100644
--- a/lib/kamal/configuration/accessory.rb
+++ b/lib/kamal/configuration/accessory.rb
@@ -214,7 +214,7 @@ class Kamal::Configuration::Accessory
 
     def extract_hosts_from_config_with_tag(tag)
       if config.raw_config.servers.is_a?(Hash)
-        config.raw_config.servers.flat_map do |(role, servers_in_role)|
+        config.raw_config.servers.flat_map do |role, servers_in_role|
           servers_in_role.collect do |host|
             if host.is_a?(Hash) && host.values.first.include?(tag)
               host.keys.first