diff --git a/playbook.yml b/playbook.yml
index b35dfba..18a33bc 100644
--- a/playbook.yml
+++ b/playbook.yml
@@ -26,8 +26,8 @@
       - ouroboros
       - mailu
 
-    smtp_host: postfix
-    smtp_port: 587
+    smtp_host: "postfix"
+    smtp_port: "587"
 
   tasks:
     - import_role:
diff --git a/roles/docker/tasks/services/fider.yml b/roles/docker/tasks/services/fider.yml
index eb1dba5..349aa30 100644
--- a/roles/docker/tasks/services/fider.yml
+++ b/roles/docker/tasks/services/fider.yml
@@ -19,7 +19,7 @@
     volumes:
       - fider_db:/var/lib/postgresql/data
     env:
-      POSTGRES_USER: fider
+      POSTGRES_USER: "fider"
       POSTGRES_PASSWORD: "{{ postgres_passwords.fider }}"
 
 - name: fider app container