diff --git services/univention-squid/conffiles/etc/squid/squid.conf services/univention-squid/conffiles/etc/squid/squid.conf
index 6ae51d6bf4..208fd870a4 100644
--- services/univention-squid/conffiles/etc/squid/squid.conf
+++ services/univention-squid/conffiles/etc/squid/squid.conf
@@ -66,6 +66,8 @@ if configRegistry.is_false('squid/cache'):
 
 transparent = 'transparent' if configRegistry.is_true('squid/transparentproxy') else ''
 print("http_port %d %s" % (int(configRegistry.get('squid/httpport', 3128)), transparent))
+if transparent:
+	print("http_port %d" % (int(configRegistry.get('squid/httpport', 3128)+1)))
 
 print('')