diff --git a/manifests/auth.pp b/manifests/auth.pp
index 3827c38741846c356b28cd9b2d297a2f7bfc3c12..275489d1420098aced87ca17c022a108d97782a9 100644
--- a/manifests/auth.pp
+++ b/manifests/auth.pp
@@ -141,8 +141,8 @@ class aes::auth (
     user        => $auth_user,
     group       => $auth_group,
     path        => $auth_home,
-    command     => "$auth_home/on_update.sh",
-    environment => [ "HOME=$auth_home", "PATH=/bin:/usr/bin" ],
+    command     => "${auth_home}/on_update.sh",
+    environment => [ "HOME=${auth_home}", 'PATH=/bin:/usr/bin' ],
     refreshonly => true,
     require     => File["${auth_home}/on_update.sh"],
     notify      => Service[$auth_service],