diff --git a/lib/net/imap.rb b/lib/net/imap.rb
index fa9b19071a..1c7e89ba14 100644
--- a/lib/net/imap.rb
+++ b/lib/net/imap.rb
@@ -1530,6 +1530,7 @@ module Net
       end
       @sock = SSLSocket.new(@sock, context)
       @sock.sync_close = true
+      @sock.hostname = @host if @sock.respond_to? :hostname=
       ssl_socket_connect(@sock, @open_timeout)
       if context.verify_mode != VERIFY_NONE
         @sock.post_connection_check(@host)