diff --git a/functions b/functions
index 3922e74..37778e7 100755
--- a/functions
+++ b/functions
@@ -385,6 +385,6 @@ service_linked_apps() {
 
 update_plugin_scheme_for_app() {
   local APP=$1
-  local MONGO_DATABASE_SCHEME=$(config_get $APP MONGO_DATABASE_SCHEME)
+  local MONGO_DATABASE_SCHEME=$(config_get "$APP" MONGO_DATABASE_SCHEME)
   PLUGIN_SCHEME=${MONGO_DATABASE_SCHEME:-$PLUGIN_SCHEME}
 }