diff --git a/lib/td/client/api.rb b/lib/td/client/api.rb
index af6d65d..c87d26c 100644
--- a/lib/td/client/api.rb
+++ b/lib/td/client/api.rb
@@ -56,7 +56,7 @@ def initialize(apikey, opts={})
     end
 
     @http_proxy = opts[:http_proxy] || ENV['HTTP_PROXY']
-    if @http_proxy = ENV['HTTP_PROXY']
+    if @http_proxy
       if @http_proxy =~ /\Ahttp:\/\/(.*)\z/
         @http_proxy = $~[1]
       end