diff --git a/lib/faraday/adapter/http.rb b/lib/faraday/adapter/http.rb
index 24cad73..598a7cc 100644
--- a/lib/faraday/adapter/http.rb
+++ b/lib/faraday/adapter/http.rb
@@ -40,7 +40,7 @@ def perform_request(env)
       def setup_connection(env)
         conn = ::HTTP
 
-        request_config(conn, env[:request]) if env[:request]
+        conn = request_config(conn, env[:request]) if env[:request]
         conn.headers(env.request_headers)
       end