Pkg upgrade says "mod_php5 has no direct installation candidates"

[Mike Clarke]

FreeBSD 10.1-RELEASE, pkg-1.4.3

I maintain most of my packages with pkg. However I build mod_php5 from ports because I need to 
use it with apache22. To stop pkg upgrade from pulling in apache24 I have locked mod_php5.

When I run pkg upgrade I see the following:
-----------------------------------------------------------------
curlew:/root# pkg upgrade
Updating FreeBSD repository catalogue...
FreeBSD repository is up-to-date.
All repositories are up-to-date.
Checking for upgrades (3 candidates):  66%
mod_php5 has no direct installation candidates, change it to mod_php5? [Y/n]: n
mod_php5 has no direct installation candidates, change it to mod_php55? [Y/n]: n
mod_php5 has no direct installation candidates, change it to mod_php56? [Y/n]: n
Checking for upgrades (3 candidates): 100%
Processing candidates (3 candidates): 100%
Checking integrity... done (0 conflicting)
Your packages are up to date.
-----------------------------------------------------------------

I've tried replying yes to "change it to mod_php5" but still get the same questions next time I run 
pkg upgrade.

As an experiment  I unlocked mod_php5 and the "no direct installation candidates" questions did 
not appear but I had to cancel the upgrade since it would replace apache22 wirh apache24,

I also have xsane and exim-sa-exim locked but have never seen similar messages for either of 
these.

It's not causing any problems because pkg is not allowed to alter mod_php5 but I'm curious what's 
causing this behaviour and how to prevent it.

-- 
Mike Clarke