diff --git a/manifests/metadata/novajoin/api.pp b/manifests/metadata/novajoin/api.pp
index 4b7ad1e83..c70f9f043 100644
--- a/manifests/metadata/novajoin/api.pp
+++ b/manifests/metadata/novajoin/api.pp
@@ -139,7 +139,7 @@ class nova::metadata::novajoin::api (
     fail('service_password is missing')
   }
 
-  if ! $nova::params::novajoin_package_name {
+  if $nova::params::novajoin_package_name == undef {
     fail("Unsupported osfamily: ${::osfamily} operatingsystem")
   }