diff --git a/.ruby-gemset b/.ruby-gemset
new file mode 100644
index 0000000..29204c2
--- /dev/null
+++ b/.ruby-gemset
@@ -0,0 +1 @@
+roadworker
diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000..7872401
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+ruby-2.6
diff --git a/lib/roadworker/route53-ext.rb b/lib/roadworker/route53-ext.rb
index d13112a..757d4a3 100644
--- a/lib/roadworker/route53-ext.rb
+++ b/lib/roadworker/route53-ext.rb
@@ -139,7 +139,7 @@ def dns_name_to_alias_target(name, options, hosted_zone_id, hosted_zone_name)
           # NLB
           region = $1.downcase
           alias_target = nlb_dns_name_to_alias_target(name, region, options)
-        elsif (s3_hosted_zone_id = S3_WEBSITE_ENDPOINTS[name.downcase]) and name =~ /\As3-website-([^.]+)\.amazonaws\.com\z/i
+        elsif (s3_hosted_zone_id = S3_WEBSITE_ENDPOINTS[name.downcase]) and name =~ /\As3-website[.-]([^.]+)\.amazonaws\.com\z/i
           region = $1.downcase
           s3_dns_name_to_alias_target(name, region, s3_hosted_zone_id)
         elsif name =~ /\.cloudfront\.net\z/i