diff --git a/lib/keystone b/lib/keystone
index 2860325..57cb24d 100644
--- a/lib/keystone
+++ b/lib/keystone
@@ -63,9 +63,6 @@
     KEYSTONE_DEPLOY=mod_wsgi
 fi
 
-# Select the token persistence backend driver
-KEYSTONE_TOKEN_BACKEND=${KEYSTONE_TOKEN_BACKEND:-sql}
-
 # Select the Identity backend driver
 KEYSTONE_IDENTITY_BACKEND=${KEYSTONE_IDENTITY_BACKEND:-sql}
 
@@ -79,7 +76,8 @@
 KEYSTONE_RESOURCE_BACKEND=${KEYSTONE_RESOURCE_BACKEND:-sql}
 
 # Select Keystone's token provider (and format)
-# Choose from 'uuid', 'pki', 'pkiz', or 'fernet'
+# Refer keystone doc for supported token provider:
+# https://docs.openstack.org/keystone/latest/admin/token-provider.html
 KEYSTONE_TOKEN_FORMAT=${KEYSTONE_TOKEN_FORMAT:-fernet}
 KEYSTONE_TOKEN_FORMAT=$(echo ${KEYSTONE_TOKEN_FORMAT} | tr '[:upper:]' '[:lower:]')
 
@@ -245,8 +243,6 @@
 
     iniset $KEYSTONE_CONF database connection `database_connection_url keystone`
 
-    iniset $KEYSTONE_CONF token driver "$KEYSTONE_TOKEN_BACKEND"
-
     # Set up logging
     if [ "$SYSLOG" != "False" ]; then
         iniset $KEYSTONE_CONF DEFAULT use_syslog "True"
@@ -443,11 +439,6 @@
     $KEYSTONE_BIN_DIR/keystone-manage --config-file $KEYSTONE_CONF db_sync
     time_stop "dbsync"
 
-    if [[ "$KEYSTONE_TOKEN_FORMAT" == "pki" || "$KEYSTONE_TOKEN_FORMAT" == "pkiz" ]]; then
-        # Set up certificates
-        rm -rf $KEYSTONE_CONF_DIR/ssl
-        $KEYSTONE_BIN_DIR/keystone-manage --config-file $KEYSTONE_CONF pki_setup
-    fi
     if [[ "$KEYSTONE_TOKEN_FORMAT" == "fernet" ]]; then
         rm -rf "$KEYSTONE_CONF_DIR/fernet-keys/"
         $KEYSTONE_BIN_DIR/keystone-manage --config-file $KEYSTONE_CONF fernet_setup