diff --git a/main.go b/main.go
index f24351d..2992dc2 100644
--- a/main.go
+++ b/main.go
@@ -24,6 +24,7 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"strings"
 	"sync"
 	"time"
 )
@@ -155,6 +156,12 @@ func addLicense(path string, fmode os.FileMode, typ string, data *copyrightData)
 	return ioutil.WriteFile(path, b, fmode)
 }
 
+var head = []string{
+	"#!",        // shell script
+	"<?xml",     // XML declaratioon
+	"<!doctype", // HTML doctype
+}
+
 func hashBang(b []byte) []byte {
 	var line []byte
 	for _, c := range b {
@@ -163,8 +170,11 @@ func hashBang(b []byte) []byte {
 			break
 		}
 	}
-	if bytes.HasPrefix(line, []byte("#!")) {
-		return line
+	first := strings.ToLower(string(line))
+	for _, h := range head {
+		if strings.HasPrefix(first, h) {
+			return line
+		}
 	}
 	return nil
 }
diff --git a/testdata/expected/file.html b/testdata/expected/file.html
index 108603b..155e2e1 100644
--- a/testdata/expected/file.html
+++ b/testdata/expected/file.html
@@ -1,3 +1,4 @@
+<!doctype html>
 <!--
  Copyright 2016 Google Inc.
  
@@ -14,5 +15,4 @@
  limitations under the License.
 -->
 
-<!doctype html>
 <p>Hello World!</p>
diff --git a/testdata/expected/file2.xml b/testdata/expected/file2.xml
new file mode 100644
index 0000000..ff225f8
--- /dev/null
+++ b/testdata/expected/file2.xml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
+<!--
+ Copyright 2016 Google Inc.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+-->
+
+<root>
+	<one>one</one>
+	<two/>
+</root>
diff --git a/testdata/initial/file2.xml b/testdata/initial/file2.xml
new file mode 100644
index 0000000..2e8daf8
--- /dev/null
+++ b/testdata/initial/file2.xml
@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
+<root>
+	<one>one</one>
+	<two/>
+</root>
