diff --git a/lib/hawk/http/instrumentation.rb b/lib/hawk/http/instrumentation.rb
index 05efb6f..e4deb97 100644
--- a/lib/hawk/http/instrumentation.rb
+++ b/lib/hawk/http/instrumentation.rb
@@ -1,3 +1,5 @@
+require 'cgi'
+
 module Hawk
   class HTTP
     module Instrumentation