HTTP Profile warning after upgrade to 11.5.1

After upgrading to 11.5.1 we see a lot of the following warnings in the local traffic log:

Fri Jul 25 14:39:58 CEST 2014   warning bigipx  tmm1[14254] 011f0012    HTTP profile option passthrough.excess_server_headers incompatible with proxy_type. Using default instead.

Does anyone know how to get rid of these?