diff --git a/lib/async/websocket/server.rb b/lib/async/websocket/server.rb
index 96d59d5..2a68d98 100644
--- a/lib/async/websocket/server.rb
+++ b/lib/async/websocket/server.rb
@@ -6,6 +6,7 @@
 
 require_relative "connection"
 require_relative "response"
+require_relative "adapters/http"
 
 require "protocol/http/middleware"