diff --git a/lib/oxidized/input/ssh.rb b/lib/oxidized/input/ssh.rb
index 2499f620a..0d26436f3 100644
--- a/lib/oxidized/input/ssh.rb
+++ b/lib/oxidized/input/ssh.rb
@@ -140,7 +140,7 @@ def make_ssh_opts
         if (proxy_port = vars(:ssh_proxy_port))
           proxy_command += "-p #{proxy_port} "
         end
-        proxy_command += "#{proxy_host} -W %h:%p"
+        proxy_command += "#{proxy_host} -W [%h]:%p"
         proxy = Net::SSH::Proxy::Command.new(proxy_command)
         ssh_opts[:proxy] = proxy
       end