diff --git a/README.md b/README.md
index b536f549..6e49989a 100644
--- a/README.md
+++ b/README.md
@@ -67,6 +67,7 @@ hash('123456');
 ```
 
 ### HashStream()
+**\[deprecated\]** use `createSha1Hash()`.
 
 Generates SHA1 hash with a transform stream.
 
@@ -80,6 +81,18 @@ fs.createReadStream('/path/to/file')
   });
 ```
 
+### createSha1Hash()
+return SHA1 hash object.
+ This is the same as calling `createHash('utf8')` in the node.js native module crypto.
+ ``` js
+const sha1 = createSha1Hash();
+ fs.createReadStream('/path/to/file')
+  .pipe(sha1)
+  .on('finish', () => {
+    console.log(sha1.read());
+  });
+```
+
 ### highlight(str, [options])
 
 Syntax highlighting for a code block.
diff --git a/lib/hash.js b/lib/hash.js
index 3112a588..57a1547e 100644
--- a/lib/hash.js
+++ b/lib/hash.js
@@ -5,10 +5,17 @@ const crypto = require('crypto');
 
 const ALGORITHM = 'sha1';
 
+function createSha1Hash() {
+  return crypto.createHash(ALGORITHM);
+}
+
+/**
+ * @deprecated
+ * createHash() is stream class.
+ */
 function HashStream() {
   Transform.call(this);
-
-  this._hash = crypto.createHash(ALGORITHM);
+  this._hash = createSha1Hash();
 }
 
 require('util').inherits(HashStream, Transform);
@@ -24,9 +31,10 @@ HashStream.prototype._flush = function(callback) {
 };
 
 exports.hash = content => {
-  const hash = crypto.createHash(ALGORITHM);
+  const hash = createSha1Hash();
   hash.update(content);
   return hash.digest();
 };
 
 exports.HashStream = HashStream;
+exports.createSha1Hash = createSha1Hash;
diff --git a/test/scripts/hash.js b/test/scripts/hash.js
index b7b2e868..820eb254 100644
--- a/test/scripts/hash.js
+++ b/test/scripts/hash.js
@@ -27,4 +27,23 @@ describe('hash', () => {
 
     stream.read().should.eql(sha1(content));
   });
+
+  it('createSha1Hash', function() {
+    var _sha1 = hash.createSha1Hash();
+    var content = '123456';
+    _sha1.update(content);
+    _sha1.digest().should.eql(sha1(content));
+  });
+
+  it('createSha1Hash - streamMode', function() {
+    var content1 = '123456';
+    var content2 = '654321';
+    var stream = hash.createSha1Hash();
+    // explicit convert
+    stream.write(Buffer.from(content1));
+    // implicit convert
+    stream.write(content2);
+    stream.end();
+    stream.read().should.eql(sha1(content1 + content2));
+  });
 });