diff --git a/yum/manifests/init.pp b/yum/manifests/init.pp
index 5c508c1..673b7ee 100644
--- a/yum/manifests/init.pp
+++ b/yum/manifests/init.pp
@@ -136,6 +136,9 @@ class yum::common {
             $osname = "el"
             $osver = regsubst($::operatingsystemrelease, '^(\d+)\..*$', '\1')
         }
+        default: {
+            fail("yum not supported on ${::operatingsystem}")
+        }
     }
 
     if $yum_proxy {
@@ -379,13 +382,13 @@ class yum::repo::dell {
                 descr      => "Dell OMSA repository - Hardware independent",
                 mirrorlist => "http://linux.dell.com/repo/hardware/latest/mirrors.cgi?osname=el\$releasever&ve&basearch=\$basearch&native=1&dellsysidpluginver=\$dellsysidpluginver",
                 gpgkey     => "puppet:///modules/yum/keys/dell-omsa.key",
-                require => Package["yum-dellsysid"],
+                require    => Package["yum-dellsysid"],
             }
             yum::repo { "dell-omsa-specific":
                 descr      => "Dell OMSA repository - Hardware specific",
                 mirrorlist => "http://linux.dell.com/repo/hardware/latest/mirrors.cgi?osname=el\$releasever&basearch=\$basearch&native=1&sys_ven_id=\$sys_ven_id&sys_dev_id=\$sys_dev_id&dellsysidpluginver=\$dellsysidpluginver",
                 gpgkey     => "puppet:///modules/yum/keys/dell-omsa.key",
-                require => Package["yum-dellsysid"],
+                require    => Package["yum-dellsysid"],
             }
         }
         default: {
@@ -592,7 +595,7 @@ class yum::repo::skype {
 }
 
 
-# Add Puppetlabs repositories
+# Add Puppetlabs products repository.
 #
 class yum::repo::puppetlabs {
 
@@ -623,6 +626,8 @@ class yum::repo::puppetlabs {
 }
 
 
+# Add Puppetlabs dependencies repository.
+#
 class yum::repo::puppetlabs::dependencies {
 
     case $::operatingsystem {