diff --git a/devstack/settings b/devstack/settings
index d1cbddc..fc5a048 100644
--- a/devstack/settings
+++ b/devstack/settings
@@ -3,17 +3,17 @@ COLLECTD_CEILOMETER_DIR=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && cd .. && pwd
 COLLECTD_BATCH_SIZE=${COLLECTD_BATCH_SIZE:-1}
 COLLECTD_BRANCH=${COLLECTD_BRANCH:-collectd-5.7}
 COLLECTD_DIR=${COLLECTD_DIR:-$DEST/collectd-$COLLECTD_BRANCH/}
-COLLECTD_INSTALL=${COLLECTD_INSTALL:-True}
+COLLECTD_INSTALL=$(trueorfalse True COLLECTD_INSTALL)
 COLLECTD_INSTALL_TYPE=${COLLECTD_INSTALL_TYPE:-'binary'}
 COLLECTD_CONF_DIR=${COLLECTD_CONF_DIR:-''}
 # this is a mirror of: git://git.verplant.org/collectd.git
 COLLECTD_REPO=${COLLECTD_REPO:-'https://github.com/collectd/collectd.git'}
 COLLECTD_PREFIX=${COLLECTD_PREFIX:-'/usr'}
 
-COLLECTD_CEILOMETER_VERBOSE=${COLLECTD_CEILOMETER_VERBOSE:-False}
+COLLECTD_CEILOMETER_VERBOSE=$(trueorfalse False COLLECTD_CEILOMETER_VERBOSE)
 
-COLLECTD_CEILOMETER_ENABLED=${COLLECTD_CEILOMETER_ENABLED:-False}
-COLLECTD_GNOCCHI_ENABLED=${COLLECTD_GNOCCHI_ENABLED:-True}
+COLLECTD_CEILOMETER_ENABLED=$(trueorfalse False COLLECTD_CEILOMETER_ENABLED)
+COLLECTD_GNOCCHI_ENABLED=$(trueorfalse True COLLECTD_GNOCCHI_ENABLED)
 
 # Configurations for Collectd LogFile plugin
 COLLECTD_LOG_FILE=${COLLECTD_LOG_FILE:-$LOGDIR/collectd.log}