diff --git a/roles/mastodon/tasks/system_setup/prepare_database.yml b/roles/mastodon/tasks/system_setup/prepare_database.yml
index c5bf567..0667b2b 100644
--- a/roles/mastodon/tasks/system_setup/prepare_database.yml
+++ b/roles/mastodon/tasks/system_setup/prepare_database.yml
@@ -35,7 +35,7 @@
     login_unix_socket: "{{ mastodon_db_login_unix_socket }}"
   register: create_local_db
   become: true
-  become_user: postgres
+  become_user: "postgres"
   when: create_remote_db is skipped
 
 - name: mastodon | postgres | Create database user {{ mastodon_db_user }}
@@ -47,5 +47,5 @@
     login_unix_socket: "{{ mastodon_db_login_unix_socket }}"
     role_attr_flags: CREATEDB
   become: true
-  become_user: postgres
+  become_user: "postgres"
   when: create_remote_db_user is skipped
\ No newline at end of file