diff --git a/bootstrapvz/providers/ec2/manifest-schema-s3.json b/bootstrapvz/providers/ec2/manifest-schema-s3.json
index ef23e51..79cd334 100644
--- a/bootstrapvz/providers/ec2/manifest-schema-s3.json
+++ b/bootstrapvz/providers/ec2/manifest-schema-s3.json
@@ -13,7 +13,8 @@
 					"type": "string"
 				},
 				"user-id": {
-					"type": "string"
+					"type": "string",
+					"pattern": "(^arn:aws:iam::\\d*:user/\\w.*$)|(^\\d{4}-\\d{4}-\\d{4}$)"
 				}
 			}
 		},