diff --git a/builtin/providers/aws/resource_aws_s3_bucket.go b/builtin/providers/aws/resource_aws_s3_bucket.go
index 6605837f8ad1..466c14febec0 100644
--- a/builtin/providers/aws/resource_aws_s3_bucket.go
+++ b/builtin/providers/aws/resource_aws_s3_bucket.go
@@ -240,7 +240,8 @@ func websiteEndpoint(s3conn *s3.S3, d *schema.ResourceData) (string, error) {
 		region = *location.LocationConstraint
 	}
 
-	// Default to us-east-1 if the bucket doesn't have a region
+	// Default to us-east-1 if the bucket doesn't have a region:
+	// http://docs.aws.amazon.com/AmazonS3/latest/API/RESTBucketGETlocation.html
 	if region == "" {
 		region = "us-east-1"
 	}