diff --git a/roles/database/tasks/main.yml b/roles/database/tasks/main.yml
index ceab30e..2976423 100644
--- a/roles/database/tasks/main.yml
+++ b/roles/database/tasks/main.yml
@@ -4,10 +4,12 @@
 
 - block:
   - debug:
-      msg: Debug
+      msg: "mysql: {{ mysql }}"
   # install software
   - import_tasks: install_mysql.yml
-    when: mysql == true
+    when: 
+      - mysql is defined
+      - mysql == true
   - import_tasks: install_postgres.yml
     when: postgres == true
   - import_tasks: install_redis.yml