diff --git a/manifests/setup.pp b/manifests/setup.pp
index fbc6e51..1a6af64 100644
--- a/manifests/setup.pp
+++ b/manifests/setup.pp
@@ -31,8 +31,8 @@ class concat::setup {
   # this goes smoothly, we should move towards completely eliminating the .sh
   # version.
   $script_name = $::osfamily? {
-    /(Windows|Solaris)/ => 'concatfragments.rb',
-    default             => 'concatfragments.sh'
+    /(?i:(Windows|Solaris))/ => 'concatfragments.rb',
+    default                  => 'concatfragments.sh'
   }
 
   $script_path = "${concatdir}/bin/${script_name}"
diff --git a/spec/unit/classes/concat_setup_spec.rb b/spec/unit/classes/concat_setup_spec.rb
index 4e83cb2..3096e73 100644
--- a/spec/unit/classes/concat_setup_spec.rb
+++ b/spec/unit/classes/concat_setup_spec.rb
@@ -61,12 +61,12 @@ describe 'concat::setup', :type => :class do
     end
   end # on osfamily Solaris
 
-  context "on osfamily Windows" do
+  context "on osfamily windows" do
     concatdir = '/foo'
     let(:facts) do
       {
         :concat_basedir => concatdir,
-        :osfamily       => 'Windows',
+        :osfamily       => 'windows',
         :id             => 'batman',
       }
     end
@@ -80,5 +80,5 @@ describe 'concat::setup', :type => :class do
         :backup => false,
       })
     end
-  end # on osfamily Windows
+  end # on osfamily windows
 end