diff --git a/manifests/init.pp b/manifests/init.pp
index 3ea92ab..068fb49 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -93,10 +93,11 @@ class apt(
     default: { fail('Valid values for disable_keys are true or false') }
   }
 
-  if($proxy_host) {
+  if ($proxy_host) {
     file { 'configure-apt-proxy':
       path    => "${apt_conf_d}/proxy",
       content => "Acquire::http::Proxy \"http://${proxy_host}:${proxy_port}\";",
+      notify  => Exec['apt_update'],
     }
   }
 }
diff --git a/spec/classes/apt_spec.rb b/spec/classes/apt_spec.rb
index 000793d..079bd59 100644
--- a/spec/classes/apt_spec.rb
+++ b/spec/classes/apt_spec.rb
@@ -117,7 +117,8 @@ describe 'apt', :type => :class do
           if param_hash[:proxy_host]
             should contain_file('configure-apt-proxy').with(
               'path'    => '/etc/apt/apt.conf.d/proxy',
-              'content' => "Acquire::http::Proxy \"http://#{param_hash[:proxy_host]}:#{param_hash[:proxy_port]}\";"
+              'content' => "Acquire::http::Proxy \"http://#{param_hash[:proxy_host]}:#{param_hash[:proxy_port]}\";",
+              'notify'  => "Exec[apt_update]"
             )
           else
             should_not contain_file('configure_apt_proxy')