diff --git a/examples/example4/README.md b/examples/example4/README.md
new file mode 100644
index 000000000..eaffa9847
--- /dev/null
+++ b/examples/example4/README.md
@@ -0,0 +1,12 @@
+NOTICE: This example is for Puppet 4 only.
+
+The following syntax that's used in profile::icinga2::agent and profile::icinga2::slave is for Puppet 4.
+```
+  @@::icinga2::object::host { $::fqdn:
+    * => merge({
+      display_name => $::hostname,
+      address      => $agent_ip,
+      target       => "/etc/icinga2/zones.d/${parent_zone}/${::hostname}.conf",
+    }, hiera_hash(icinga2::host)),
+  }
+```
diff --git a/examples/example4/profile/manifests/agent.pp b/examples/example4/profile/manifests/agent.pp
index 24120170e..a13601cbd 100644
--- a/examples/example4/profile/manifests/agent.pp
+++ b/examples/example4/profile/manifests/agent.pp
@@ -1,3 +1,4 @@
+# Notice: this code contains Puppet 4 syntax! It doesn't run on Puppet 3.
 class profile::icinga2::agent(
   $parent_endpoints,
   $parent_zone,
@@ -48,6 +49,7 @@
   }
 
   @@::icinga2::object::host { $::fqdn:
+    # Puppet 4 syntax
     * => merge({
       display_name => $::hostname,
       address      => $agent_ip,
diff --git a/examples/example4/profile/manifests/slave.pp b/examples/example4/profile/manifests/slave.pp
index a019449a7..0b4006d9c 100644
--- a/examples/example4/profile/manifests/slave.pp
+++ b/examples/example4/profile/manifests/slave.pp
@@ -1,3 +1,4 @@
+# Notice: this code contains Puppet 4 syntax! It doesn't run on Puppet 3.
 class profile::icinga2::slave(
   $slave_zone,
   $parent_endpoints,
@@ -64,6 +65,7 @@
   ::Icinga2::Object::Zone <<| tag == "icinga2::parent::${slave_zone}" |>>
 
   @@::icinga2::object::host { $::fqdn:
+    # Puppet 4 syntax
     * => deep_merge({
       display_name => $::hostname,
       address      => $slave_ip,