diff --git a/lib/db-api/comment.js b/lib/db-api/comment.js
index f0121e42c7..3c7356dfd0 100644
--- a/lib/db-api/comment.js
+++ b/lib/db-api/comment.js
@@ -50,6 +50,21 @@ exports.all = function all(fn) {
   return this;
 };
 
+/**
+ * Get all comments
+ *
+ * @param {ObjectId} id comment id
+ * @param {Function} fn callback function
+ *   - 'err' error found while process or `null`
+ *   - 'comments' list items found or `undefined`
+ * @return {Module} `comment` module
+ * @api public
+ */
+
+exports.getById = function getById(id, fn) {
+  return Comment.findById(id, fn);
+};
+
 /**
  * Create comment for `proposal` by `author`
  * with `text`
diff --git a/lib/db-api/notification.js b/lib/db-api/notification.js
index d08af7367d..805598f008 100644
--- a/lib/db-api/notification.js
+++ b/lib/db-api/notification.js
@@ -6,6 +6,7 @@ var mongoose = require('mongoose');
 var Notification = mongoose.model('Notification');
 var User = require('./user');
 var Topic = require('./topic');
+var Comment = require('./comment');
 var log = require('debug')('democracyos:db-api:notification');
 var utils = require('lib/utils');
 var pluck = utils.pluck;
@@ -79,12 +80,14 @@ function map (eventData) {
 const mappers = {
   reply: function mapReply (eventData) {
     return new Promise((resolve, reject) => {
-      getUser(eventData.to)
-      .then(user => resolve({
+      getComment(eventData.comment.id)
+      .then(comment => getTopic(comment.reference))
+      .then(topic => resolve({
         type: 'reply',
         relatedUser: eventData.reply.author.id,
-        user: user,
-        comment: eventData.reply.id
+        user: eventData.comment.author.id,
+        comment: eventData.comment.id,
+        topic: topic.id
       }))
       .catch(err => reject(err));
     });
@@ -95,8 +98,8 @@ const mappers = {
       getTopic(eventData.comment.reference)
       .then(topic => resolve({
         type: 'upvote',
-        user: topic.author.id,
-        relatedUser: eventData.user.id,
+        user: eventData.comment.author._id,
+        relatedUser: eventData.user._id,
         topic: topic.id,
         comment: eventData.comment.id
       }))
@@ -109,8 +112,8 @@ const mappers = {
       getTopic(eventData.comment.reference)
       .then(topic => resolve({
         type: 'downvote',
-        user: topic.author.id,
-        relatedUser: eventData.user.id,
+        user: eventData.comment.author._id,
+        relatedUser: eventData.user._id,
         topic: topic.id,
         comment: eventData.comment.id
       }))
@@ -147,6 +150,20 @@ function getUser (email) {
   });
 }
 
+function getComment (id) {
+  return new Promise((resolve, reject) => {
+    Comment.getById(id, (err, doc) => {
+      if (err) {
+        return reject(err);
+      } else if (!doc) {
+        return reject(new Error('comment not found'))
+      }
+
+      return resolve(doc);
+    })
+  });
+}
+
 function getTopic (id) {
   return new Promise((resolve, reject) => {
     Topic.searchOne(id, function (err, topic) {