diff --git a/lib/document.js b/lib/document.js
index 7603fbe..8fa8c34 100644
--- a/lib/document.js
+++ b/lib/document.js
@@ -113,7 +113,7 @@
 
     static get(ids, fetchReference = true) {
       return new Promise((resolve, reject) => {
-        var x;
+        var previousError, x;
         /*
         Fetch the document with id or ids.
         If the document is not exist, it will return null.
@@ -144,6 +144,7 @@
         }
         // fetch documents
         if (ids.constructor === Array) {
+          previousError = new Error('From previous stack');
           this._es.mget({
             index: this.getIndexName(),
             type: this.getDocumentType(),
@@ -153,6 +154,7 @@
           }, (error, response) => {
             var dbField, doc, i, item, len, property, propertyName, ref, ref1, ref2, result;
             if (error) {
+              error.stack += previousError.stack;
               return reject(error);
             }
             result = [];
@@ -190,6 +192,7 @@
           return;
         }
         // fetch the document
+        previousError = new Error('From previous stack');
         return this._es.get({
           index: this.getIndexName(),
           type: this.getDocumentType(),
@@ -197,6 +200,7 @@
         }, (error, response) => {
           var args, dbField, document, property, propertyName, ref, ref1;
           if (error) {
+            error.stack += previousError.stack;
             if (error.status === 404) {
               return resolve(null);
             }
@@ -236,12 +240,15 @@
         @param id {string} The documents' id.
         @returns {promise<bool>}
         */
+        var previousError;
+        previousError = new Error('From previous stack');
         return this._es.exists({
           index: this.getIndexName(),
           type: this.getDocumentType(),
           id: id
         }, function(error, response) {
           if (error) {
+            error.stack += previousError.stack;
             return reject(error);
           }
           return resolve(response);
@@ -269,6 +276,7 @@
 
     static refresh(args = {}) {
       return new Promise((resolve, reject) => {
+        var previousError;
         /*
         Explicitly refresh one or more index, making all operations performed since the last refresh available for search.
         https://www.elastic.co/guide/en/elasticsearch/client/javascript-api/current/api-reference-5-6.html#api-indices-refresh-5-6
@@ -276,8 +284,10 @@
         @returns {promise}
         */
         args.index = this.getIndexName();
+        previousError = new Error('From previous stack');
         return this._es.indices.refresh(args, function(error) {
           if (error) {
+            error.stack += previousError.stack;
             return reject(error);
           }
           return resolve();
@@ -295,10 +305,13 @@
       var closeIndex, createIndex, openIndex, putMapping, putSettings;
       createIndex = () => {
         return new Promise((resolve, reject) => {
+          var previousError;
+          previousError = new Error('From previous stack');
           return this._es.indices.create({
             index: this.getIndexName()
           }, function(error, response) {
             if (error && error.status !== 400) {
+              error.stack += previousError.stack;
               return reject(error);
             }
             return setTimeout(function() {
@@ -309,10 +322,13 @@
       };
       closeIndex = () => {
         return new Promise((resolve, reject) => {
+          var previousError;
+          previousError = new Error('From previous stack');
           return this._es.indices.close({
             index: this.getIndexName()
           }, function(error, response) {
             if (error) {
+              error.stack += previousError.stack;
               return reject(error);
             }
             return resolve(response);
@@ -321,9 +337,11 @@
       };
       putSettings = () => {
         return new Promise((resolve, reject) => {
+          var previousError;
           if (!this._settings) {
             return resolve();
           }
+          previousError = new Error('From previous stack');
           return this._es.indices.putSettings({
             index: this.getIndexName(),
             body: {
@@ -333,6 +351,7 @@
             }
           }, function(error, response) {
             if (error) {
+              error.stack += previousError.stack;
               return reject(error);
             }
             return resolve(response);
@@ -341,7 +360,7 @@
       };
       putMapping = () => {
         return new Promise((resolve, reject) => {
-          var field, mapping, property, propertyName, ref, ref1, ref2, ref3;
+          var field, mapping, previousError, property, propertyName, ref, ref1, ref2, ref3;
           mapping = {};
           ref = this._properties;
           for (propertyName in ref) {
@@ -428,6 +447,7 @@
               mapping[(ref3 = property.dbField) != null ? ref3 : propertyName] = field;
             }
           }
+          previousError = new Error('From previous stack');
           return this._es.indices.putMapping({
             index: this.getIndexName(),
             type: this.getDocumentType(),
@@ -436,6 +456,7 @@
             }
           }, function(error, response) {
             if (error) {
+              error.stack += previousError.stack;
               return reject(error);
             }
             return resolve(response);
@@ -444,10 +465,13 @@
       };
       openIndex = () => {
         return new Promise((resolve, reject) => {
+          var previousError;
+          previousError = new Error('From previous stack');
           return this._es.indices.open({
             index: this.getIndexName()
           }, function(error, response) {
             if (error) {
+              error.stack += previousError.stack;
               return reject(error);
             }
             return resolve(response);
@@ -464,7 +488,7 @@
 
     save(refresh = false) {
       return new Promise((resolve, reject) => {
-        var args, convertError, dbFieldName, document, error, property, propertyName, ref, ref1, ref2;
+        var args, convertError, dbFieldName, document, error, previousError, property, propertyName, ref, ref1, ref2;
         /*
         Save this document.
         @param refresh {bool} Refresh the index after performing the operation.
@@ -509,8 +533,10 @@
             body: document
           };
         }
+        previousError = new Error('From previous stack');
         return this.constructor._es.index(args, (error, response) => {
           if (error) {
+            error.stack += previousError.stack;
             return reject(error);
           }
           this.id = response._id;
@@ -526,6 +552,8 @@
         Delete this document.
         @returns {promise<Document>}
         */
+        var previousError;
+        previousError = new Error('From previous stack');
         return this.constructor._es.delete({
           index: this.constructor.getIndexName(),
           type: this.constructor.getDocumentType(),
@@ -533,6 +561,7 @@
           id: this.id
         }, (error) => {
           if (error) {
+            error.stack += previousError.stack;
             return reject(error);
           }
           return resolve(this);
diff --git a/lib/query.js b/lib/query.js
index f341546..ec5a110 100644
--- a/lib/query.js
+++ b/lib/query.js
@@ -267,7 +267,7 @@
 
     fetch(args = {}) {
       return new Promise((resolve, reject) => {
-        var queryObject;
+        var previousError, queryObject;
         /*
         Fetch documents by this query.
         @param args {object}
@@ -293,6 +293,7 @@
           });
           return;
         }
+        previousError = new Error('From previous stack');
         return this.documentClass._es.search({
           index: this.documentClass.getIndexName(),
           body: {
@@ -305,6 +306,7 @@
         }, (error, response) => {
           var items, total;
           if (error) {
+            error.stack += previousError.stack;
             return reject(error);
           }
           items = (() => {
@@ -374,8 +376,9 @@
         Count documents by the query.
         @returns {promise<number>}
         */
-        var queryObject;
+        var previousError, queryObject;
         queryObject = this.compileQueries();
+        previousError = new Error('From previous stack');
         return this.documentClass._es.count({
           index: this.documentClass.getIndexName(),
           body: {
@@ -383,6 +386,7 @@
           }
         }, function(error, response) {
           if (error) {
+            error.stack += previousError.stack;
             return reject(error);
           }
           return resolve(response.count);
@@ -398,7 +402,7 @@
         @param field {string} The property name of the document.
         @returns {promise<number>}
         */
-        var allFields, dbField, property, propertyName, queryObject, ref, ref1, ref2, ref3;
+        var allFields, dbField, previousError, property, propertyName, queryObject, ref, ref1, ref2, ref3;
         allFields = [];
         ref = this.documentClass._properties;
         for (propertyName in ref) {
@@ -416,6 +420,7 @@
         if (queryObject.isContainsEmpty) {
           return resolve(0);
         }
+        previousError = new Error('From previous stack');
         return this.documentClass._es.search({
           index: this.documentClass.getIndexName(),
           body: {
@@ -431,6 +436,7 @@
           size: 0
         }, (error, response) => {
           if (error) {
+            error.stack += previousError.stack;
             return reject(error);
           }
           return resolve(response.aggregations.intraday_return.value);
@@ -440,7 +446,7 @@
 
     groupBy(field, args = {}) {
       return new Promise((resolve, reject) => {
-        var allFields, dbField, property, propertyName, queryObject, ref, ref1, ref2, ref3, ref4;
+        var allFields, dbField, previousError, property, propertyName, queryObject, ref, ref1, ref2, ref3, ref4;
         /*
         Aggregations
         http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-aggregations.html
@@ -481,6 +487,7 @@
         if (queryObject.isContainsEmpty) {
           return resolve([]);
         }
+        previousError = new Error('From previous stack');
         return this.documentClass._es.search({
           index: this.documentClass.getIndexName(),
           body: {
@@ -500,6 +507,7 @@
           size: 0
         }, (error, response) => {
           if (error) {
+            error.stack += previousError.stack;
             return reject(error);
           }
           return resolve(response.aggregations.genres.buckets);
diff --git a/package.json b/package.json
index e1444af..058d5dc 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "enju",
-  "version": "5.1.2",
+  "version": "5.2.0",
   "description": "An elasticsearch client on node.js written in CoffeeScript.",
   "main": "index.js",
   "scripts": {