diff --git a/lib/v2/encoder.js b/lib/v2/encoder.js
index be7dcc6..b2b8102 100644
--- a/lib/v2/encoder.js
+++ b/lib/v2/encoder.js
@@ -142,7 +142,7 @@ proto.writeInt = function (val) {
  * ```
  */
 proto.writeLong = function (val) {
-  if (typeof val !== 'number' && utility.isSafeNumberString(val)) {
+  if (typeof val !== 'number' && utility.isSafeNumberString(val + '')) {
     val = Number(val);
   }
 
diff --git a/test/long.test.js b/test/long.test.js
index 1ce594f..c43a517 100644
--- a/test/long.test.js
+++ b/test/long.test.js
@@ -46,6 +46,10 @@ describe('long.test.js', function () {
       hessian.encode(java.long(0)),
       new Buffer(['L'.charCodeAt(0), 0, 0, 0, 0, 0, 0, 0, 0])
     );
+    assert.deepEqual(
+      hessian.encode(Long.fromNumber(0)),
+      new Buffer(['L'.charCodeAt(0), 0, 0, 0, 0, 0, 0, 0, 0])
+    );
   });
 
   it('should write and read equal java impl', function () {