diff --git a/shibboleth-appliance.json b/shibboleth-appliance.json
index b937963..873f19c 100644
--- a/shibboleth-appliance.json
+++ b/shibboleth-appliance.json
@@ -6,6 +6,7 @@
       "disk_size": "8192",
       "memory": "6122",
       "cpus": "2",
+      "guest_os_type": "RedHat_64",
       "ssh_username": "centos",
       "ssh_password": "centos",
       "region": "us-west-1",
@@ -39,7 +40,8 @@
         "disk_size": "{{user `disk_size`}}",
         "vboxmanage": [
             ["modifyvm", "{{.Name}}", "--memory", "{{user `memory`}}"],
-            ["modifyvm", "{{.Name}}", "--cpus", "{{user `cpus`}}"]
+            ["modifyvm", "{{.Name}}", "--cpus", "{{user `cpus`}}"],
+            ["modifyvm", "{{.Name}}", "--ostype", "{{user `guest_os_type`}}"]
         ],
         "iso_url": "http://mirror.vcu.edu/pub/gnu+linux/centos/7/isos/x86_64/CentOS-7-x86_64-Minimal-1511.iso",
         "iso_checksum": "f90e4d28fa377669b2db16cbcb451fcb9a89d2460e3645993e30e137ac37d284",