diff --git a/s3/bucket_test.go b/s3/bucket_test.go
index 557cbdd..e6c4b84 100644
--- a/s3/bucket_test.go
+++ b/s3/bucket_test.go
@@ -96,19 +96,25 @@ func TestPutAll(t *testing.T) {
 	assert.NoError(err)
 
 	// add spool
-	obj2 := NewPutObjectString("testString")
-	b.AddObject(obj2, testS3Path+"_string")
+	obj := NewPutObjectString("testString-01")
+	b.AddObject(obj, testS3Path+"_string1")
+	obj2 := NewPutObjectString("testString-02")
+	b.AddObject(obj2, testS3Path+"_string2")
 
 	// write data
 	err = b.PutAll()
 	assert.NoError(err)
 
 	// verify
-	data, err := b.GetObjectByte(testS3Path + "_string")
+	data, err := b.GetObjectByte(testS3Path + "_string1")
+	assert.NoError(err)
+	assert.Equal("testString-01", string(data))
+
+	data, err = b.GetObjectByte(testS3Path + "_string2")
 	assert.NoError(err)
-	assert.Equal("testString", string(data))
+	assert.Equal("testString-02", string(data))
 
-	// Data error is occured on Travis CI, Skip it.
+	// Data copy error is occured on Travis CI, Skip it.
 	// f := openFile(t)
 	// defer f.Close()
 	// obj := NewPutObjectCopy(f)