diff --git a/manifests/params.pp b/manifests/params.pp
index 6d6545a..1dca377 100644
--- a/manifests/params.pp
+++ b/manifests/params.pp
@@ -23,17 +23,17 @@
         }
       } else {
         case $::operatingsystemmajrelease {
-          5: {
+          '5': {
             $udev_package    = 'udev'
             $udevtrigger     = 'udevtrigger'
             $udevlogpriority = 'udevcontrol log_priority'
           }
-          6: {
+          '6': {
             $udev_package    = 'udev'
             $udevtrigger     = 'udevadm trigger'
             $udevlogpriority = 'udevadm control --log-priority'
           }
-          7: {
+          '7': {
             $udev_package    = 'systemd'
             $udevtrigger     = 'udevadm trigger'
             $udevlogpriority = 'udevadm control --log-priority'