diff --git a/templates/rgloader.rb b/templates/rgloader.rb
index 53f19cb80..c3c05b095 100644
--- a/templates/rgloader.rb
+++ b/templates/rgloader.rb
@@ -4,4 +4,6 @@
 if ENV["VAGRANT_INSTALLER_EMBEDDED_DIR"]
   require File.expand_path(
     "rgloader/loader", ENV["VAGRANT_INSTALLER_EMBEDDED_DIR"])
+else
+  raise "Encoded files can't be read outside of the Vagrant installer."
 end