diff --git a/ssh/manifests/init.pp b/ssh/manifests/init.pp
index c47a78d..166fdef 100644
--- a/ssh/manifests/init.pp
+++ b/ssh/manifests/init.pp
@@ -12,14 +12,19 @@ class ssh::known_hosts {
         },
     }
 
+    $shortname = inline_template("<%= homename.split('.')[0] %>")
+
+    if $::ec2_public_ipv4 {
+        $aliases = [ $shortname, $::ipaddress, $::ec2_public_ipv4 ]
+    } else {
+        $aliases = [ $shortname, $::ipaddress ]
+    }
+
     @@sshkey { $homename:
         ensure       => present,
         type         => rsa,
         key          => $sshrsakey,
-        host_aliases => [
-          inline_template("<%= homename.split('.')[0] %>"),
-          $::ipaddress,
-        ],
+        host_aliases => $aliases,
         require      => File["/etc/ssh/ssh_known_hosts"],
     }