diff --git a/website/source/docs/builders/amazon-ebs.html.md b/website/source/docs/builders/amazon-ebs.html.md
index 11850a2d5..9bdee6bd1 100644
--- a/website/source/docs/builders/amazon-ebs.html.md
+++ b/website/source/docs/builders/amazon-ebs.html.md
@@ -163,6 +163,8 @@ builder.
     process). Default `false`.
 
 -   `kms_key_id` (string) - The ID of the KMS key to use for boot volume encryption.
+    This only applies to the main `region`, other regions where the AMI will be copied
+    will be encrypted by the default EBS KMS key.
 
 -   `iam_instance_profile` (string) - The name of an [IAM instance
     profile](https://docs.aws.amazon.com/IAM/latest/UserGuide/instance-profiles.html)