diff --git a/test/dev_server_proxy_test.rb b/test/dev_server_proxy_test.rb
index b8bee3a7..0b222d14 100644
--- a/test/dev_server_proxy_test.rb
+++ b/test/dev_server_proxy_test.rb
@@ -40,6 +40,14 @@ def test_vite_asset
     assert_forwarded to: "/vite-production/application.js"
   end
 
+  def test_forwards_to_configured_backend
+    get_with_dev_server_running "/vite-production/application.js"
+
+    env = JSON.parse(last_response.body)
+
+    assert_equal ViteRuby.config.origin, env["rack.backend"]
+  end
+
   def test_vite_client
     get_with_dev_server_running "/@vite/client"
 
diff --git a/vite_ruby/lib/vite_ruby/dev_server_proxy.rb b/vite_ruby/lib/vite_ruby/dev_server_proxy.rb
index 6d877977..7e4a9523 100644
--- a/vite_ruby/lib/vite_ruby/dev_server_proxy.rb
+++ b/vite_ruby/lib/vite_ruby/dev_server_proxy.rb
@@ -44,6 +44,7 @@ def normalize_uri(uri)
   def forward_to_vite_dev_server(env)
     rewrite_uri_for_vite(env)
     env["QUERY_STRING"] ||= ""
+    env["rack.backend"] = URI(config.origin)
     env["HTTP_HOST"] = env["HTTP_X_FORWARDED_HOST"] = config.host
     env["HTTP_X_FORWARDED_SERVER"] = config.host_with_port
     env["HTTP_PORT"] = env["HTTP_X_FORWARDED_PORT"] = config.port.to_s