Configuring mod_tile and renderd for memcache

I have my mod_tile.config set up like this

# This is the Apache server configuration file for providing OSM tile support
# through mod_tile

LoadModule tile_module modules/mod_tile.so

<VirtualHost *:80>
    ServerName tile.openstreetmap.org
    ServerAlias a.tile.openstreetmap.org b.tile.openstreetmap.org c.tile.openstreetmap.org d.tile.openstreetmap.org
    DocumentRoot /var/www/html

# Specify the default base storage path for where tiles live. A number of different storage backends
# are available, that can be used for storing tiles.  Currently these are a file based storage, a memcached
# based storage and a RADOS based storage.
# The file based storage uses a simple file path as its storage path ( /path/to/tiledir )
# The RADOS based storage takes a location to the rados config file and a pool name ( rados://poolname/path/to/ceph.conf )
# The memcached based storage currently has no configuration options and always connects to memcached on localhost ( memcached:// )
#
# The storage path can be overwritten on a style by style basis from the style TileConfigFile
    ModTileTileDir memcached://
...

and my renderd.config set up like this

[renderd]
num_threads=4
tile_dir=memcached://localhost:11211
stats_file=/var/run/renderd/renderd.stats

[mapnik]
plugins_dir=/usr/lib/mapnik/3.0/input
font_dir=/usr/share/fonts/truetype
font_dir_recurse=1

[ajt]
URI=/hot/
TILEDIR=memcached://localhost:11211
XML=/home/renderaccount/src/openstreetmap-carto/mapnik.xml
HOST=localhost
TILESIZE=256
MAXZOOM=20

yet I am receiving this error:

renderd[10095]: Loading parameterization function for debug: init_storage_backend: initialising memcached storage backend at: memcached://
ERROR: init_storage_memcached: Support for memcached has not been compiled into this program

How do I compile support for memcached into mod_tile and renderd?