diff --git a/spec/defines/dhcp_spec.rb b/spec/defines/dhcp_spec.rb
index 2480157..61611fd 100644
--- a/spec/defines/dhcp_spec.rb
+++ b/spec/defines/dhcp_spec.rb
@@ -1,42 +1,60 @@
 require 'spec_helper'
 
 describe 'debnet::iface::dhcp' do
   let(:title) { 'eth0' }
   let(:facts) {{
     :concat_basedir => '/var/lib/puppet/concat',
   }}
 
   context 'eth0 standard' do
     it {
       should contain_package('isc-dhcp-client')
       should contain_debnet__iface('eth0').with({
         'method' => 'dhcp',
         'family' => 'inet',
       })
     }
   end
 
   context 'eth0 with params' do
     let(:params) {{
       :hostname  => 'test',
       :metric    => '20',
       :leasetime => '1234',
       :vendor    => 'vendor',
       :client    => 'client',
       :hwaddress => '11:22:33:44:55:66',
     }}
     it {
       should contain_package('isc-dhcp-client')
       should contain_debnet__iface('eth0').with({
         'method'    => 'dhcp',
         'family'    => 'inet',
         'hostname'  => 'test',
         'metric'    => '20',
         'leasetime' => '1234',
         'vendor'    => 'vendor',
         'client'    => 'client',
         'hwaddress' => '11:22:33:44:55:66',
       })
     }
   end
+
+  context 'eth0 with bad hostname' do
+    let(:params) {{
+      :hostname  => 'test.example.org',
+    }}
+    it {
+      expect { should raise_error(Puppet::Error) }
+    }
+  end
+
+  context 'eth0 with bad hwaddress' do
+    let(:params) {{
+      :hwaddress => '11:22:33:44:55:66:xx',
+    }}
+    it {
+      expect { should raise_error(Puppet::Error) }
+    }
+  end
 end