diff --git a/raid/manifests/init.pp b/raid/manifests/init.pp
index 30c621f..0dbbb41 100644
--- a/raid/manifests/init.pp
+++ b/raid/manifests/init.pp
@@ -52,7 +52,7 @@ class raid::tools::megacli {
         fail("Must define \$raid_megacli_package")
     }
 
-    if ! $::operatingsystem in ["CentOS", "RedHat"] {
+    if ! ($::operatingsystem in ["CentOS", "RedHat"]) {
         fail("raid::tools::megacli not supported in ${::operatingsystem}")
     }