diff --git a/lib/mysql/protocol.rb b/lib/mysql/protocol.rb
index f19d33e..42736c0 100644
--- a/lib/mysql/protocol.rb
+++ b/lib/mysql/protocol.rb
@@ -163,7 +163,7 @@ def initialize(host, port, socket, conn_timeout, read_timeout, write_timeout)
       @write_timeout = write_timeout
       begin
         Timeout.timeout conn_timeout do
-          if host.nil? or host.empty? or host == "localhost"
+          if host.nil? or host.empty?
             socket ||= ENV["MYSQL_UNIX_PORT"] || MYSQL_UNIX_PORT
             @sock = UNIXSocket.new socket
           else