diff --git a/lib/kamal/configuration/proxy.rb b/lib/kamal/configuration/proxy.rb
index ed108a02..653b93d4 100644
--- a/lib/kamal/configuration/proxy.rb
+++ b/lib/kamal/configuration/proxy.rb
@@ -28,7 +28,7 @@ class Kamal::Configuration::Proxy
 
   def deploy_options
     {
-      host: hosts.present? ? hosts.join(",") : nil,
+      host: hosts,
       tls: proxy_config["ssl"] ? true : nil,
       "deploy-timeout": seconds_duration(config.deploy_timeout),
       "drain-timeout": seconds_duration(config.drain_timeout),
diff --git a/test/commands/app_test.rb b/test/commands/app_test.rb
index 6d444569..e2a6fe83 100644
--- a/test/commands/app_test.rb
+++ b/test/commands/app_test.rb
@@ -131,7 +131,7 @@ class CommandsAppTest < ActiveSupport::TestCase
     @config[:proxy] = { "ssl" => true, "hosts" => [ "example.com", "anotherexample.com" ] }
 
     assert_equal \
-      "docker exec kamal-proxy kamal-proxy deploy app-web --target \"172.1.0.2:80\" --host \"example.com,anotherexample.com\" --tls --deploy-timeout \"30s\" --drain-timeout \"30s\" --buffer-requests --buffer-responses --log-request-header \"Cache-Control\" --log-request-header \"Last-Modified\" --log-request-header \"User-Agent\"",
+      "docker exec kamal-proxy kamal-proxy deploy app-web --target \"172.1.0.2:80\" --host \"example.com\" --host \"anotherexample.com\" --tls --deploy-timeout \"30s\" --drain-timeout \"30s\" --buffer-requests --buffer-responses --log-request-header \"Cache-Control\" --log-request-header \"Last-Modified\" --log-request-header \"User-Agent\"",
       new_command.deploy(target: "172.1.0.2").join(" ")
   end