diff --git a/go.sum b/go.sum
index d7beeda..42ba84f 100644
--- a/go.sum
+++ b/go.sum
@@ -96,6 +96,7 @@ github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181112202954-3d3f9f413869 h1:kkXA53yGe04D0adEYJwEVQjeBppL01Exg+fnMjfUraU=
@@ -132,4 +133,5 @@ gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
 gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.5 h1:ymVxjfMaHvXD8RqPRmzHHsB3VvucivSkIAvJFDI5O3c=
 gopkg.in/yaml.v2 v2.2.5/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/pkg/bookmark/repository_mongodb.go b/pkg/bookmark/repository_mongodb.go
index bde7fa5..ae0d254 100644
--- a/pkg/bookmark/repository_mongodb.go
+++ b/pkg/bookmark/repository_mongodb.go
@@ -1,6 +1,7 @@
 package bookmark
 
 import (
+	"fmt"
 	"github.com/eminetto/clean-architecture-go/pkg/entity"
 	"github.com/juju/mgosession"
 	mgo "gopkg.in/mgo.v2"
@@ -43,7 +44,7 @@ func (r *MongoRepository) Store(b *entity.Bookmark) (entity.ID, error) {
 	coll := session.DB(r.db).C("bookmark")
 	err := coll.Insert(b)
 	if err != nil {
-		return entity.ID(0), err
+		return entity.ID(fmt.Sprint(0)), err
 	}
 	return b.ID, nil
 }