diff --git a/lib/msf/core/exploit/http/client.rb b/lib/msf/core/exploit/http/client.rb
index 25af7336ab..93b17b8652 100644
--- a/lib/msf/core/exploit/http/client.rb
+++ b/lib/msf/core/exploit/http/client.rb
@@ -822,7 +822,7 @@ module Exploit::Remote::HttpClient
     }
 
     res.headers.each_pair do |k,v|
-      hname = k.to_s.downcase.gsub('-', '_').gsub(/[^a-z0-9_]+/, '')
+      hname = k.to_s.downcase.tr('-', '_').gsub(/[^a-z0-9_]+/, '')
       next unless hname.length > 0
 
       # Set-Cookie >        :header_set_cookie       => JSESSIONID=AAASD23423452