diff --git a/examples/cloud-sql-mysql/main.tf b/examples/cloud-sql-mysql/main.tf
index 27c2ab9..2d629b7 100644
--- a/examples/cloud-sql-mysql/main.tf
+++ b/examples/cloud-sql-mysql/main.tf
@@ -10,6 +10,9 @@ terraform {
 }
 
 module "mysql" {
+  # When using these modules in your own templates, you will need to use a Git URL with a ref attribute that pins you
+  # to a specific version of the modules, such as the following example:
+  # source = "git::git@github.com:gruntwork-io/terraform-google-sql.git//modules/mysql?ref=v0.1.0"
   source           = "../../modules/mysql"
 
   project = "${var.project}"