diff --git a/package-lock.json b/package-lock.json
index cdef413604d4b..4bccc97faab10 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4473,7 +4473,6 @@
 			"version": "0.1.7",
 			"resolved": "https://registry.npmjs.org/errno/-/errno-0.1.7.tgz",
 			"integrity": "sha512-MfrRBDWzIWifgq6tJj60gkAwtLNb6sQPlcFrSOflcP1aFmmruKQ2wRnze/8V6kgyz7H3FF8Npzv78mZ7XLLflg==",
-			"optional": true,
 			"requires": {
 				"prr": "1.0.1"
 			}
@@ -9478,8 +9477,7 @@
 		"natives": {
 			"version": "1.1.4",
 			"resolved": "https://registry.npmjs.org/natives/-/natives-1.1.4.tgz",
-			"integrity": "sha512-Q29yeg9aFKwhLVdkTAejM/HvYG0Y1Am1+HUkFQGn5k2j8GS+v60TVmZh6nujpEAj/qql+wGUrlryO8bF+b1jEg==",
-			"optional": true
+			"integrity": "sha512-Q29yeg9aFKwhLVdkTAejM/HvYG0Y1Am1+HUkFQGn5k2j8GS+v60TVmZh6nujpEAj/qql+wGUrlryO8bF+b1jEg=="
 		},
 		"natural-compare": {
 			"version": "1.4.0",
@@ -11211,8 +11209,7 @@
 		"prr": {
 			"version": "1.0.1",
 			"resolved": "https://registry.npmjs.org/prr/-/prr-1.0.1.tgz",
-			"integrity": "sha1-0/wRS6BplaRexok/SEzrHXj19HY=",
-			"optional": true
+			"integrity": "sha1-0/wRS6BplaRexok/SEzrHXj19HY="
 		},
 		"pseudomap": {
 			"version": "1.0.2",
diff --git a/packages/rocketchat-api/server/v1/chat.js b/packages/rocketchat-api/server/v1/chat.js
index 3bfaacea2907d..d6d06997d588f 100644
--- a/packages/rocketchat-api/server/v1/chat.js
+++ b/packages/rocketchat-api/server/v1/chat.js
@@ -274,7 +274,7 @@ RocketChat.API.v1.addRoute('chat.react', { authRequired: true }, {
 			throw new Meteor.Error('error-emoji-param-not-provided', 'The required "emoji" param is missing.');
 		}
 
-		Meteor.runAsUser(this.userId, () => Meteor.call('setReaction', emoji, msg._id));
+		Meteor.runAsUser(this.userId, () => Meteor.call('setReaction', emoji, msg._id, this.bodyParams.shouldReact));
 
 		return RocketChat.API.v1.success();
 	}
diff --git a/packages/rocketchat-reactions/setReaction.js b/packages/rocketchat-reactions/setReaction.js
index 89df6b8139f6e..2cf5a8c7bdc79 100644
--- a/packages/rocketchat-reactions/setReaction.js
+++ b/packages/rocketchat-reactions/setReaction.js
@@ -1,8 +1,16 @@
 /* globals msgStream */
 import _ from 'underscore';
 
+const removeUserReaction = (message, reaction, username) => {
+	message.reactions[reaction].usernames.splice(message.reactions[reaction].usernames.indexOf(username), 1);
+	if (message.reactions[reaction].usernames.length === 0) {
+		delete message.reactions[reaction];
+	}
+	return message;
+};
+
 Meteor.methods({
-	setReaction(reaction, messageId) {
+	setReaction(reaction, messageId, shouldReact) {
 		if (!Meteor.userId()) {
 			throw new Meteor.Error('error-invalid-user', 'Invalid user', { method: 'setReaction' });
 		}
@@ -39,12 +47,12 @@ Meteor.methods({
 			return false;
 		}
 
-		if (message.reactions && message.reactions[reaction] && message.reactions[reaction].usernames.indexOf(user.username) !== -1) {
-			message.reactions[reaction].usernames.splice(message.reactions[reaction].usernames.indexOf(user.username), 1);
-
-			if (message.reactions[reaction].usernames.length === 0) {
-				delete message.reactions[reaction];
-			}
+		const userAlreadyReacted = Boolean(message.reactions) && message.reactions[reaction] && message.reactions[reaction].usernames.indexOf(user.username) !== -1;
+		if (userAlreadyReacted === shouldReact) {
+			return;
+		}
+		if (userAlreadyReacted) {
+			removeUserReaction(message, reaction, user.username);
 
 			if (_.isEmpty(message.reactions)) {
 				delete message.reactions;
diff --git a/tests/end-to-end/api/05-chat.js b/tests/end-to-end/api/05-chat.js
index a4f56aec3fc13..07736412471b0 100644
--- a/tests/end-to-end/api/05-chat.js
+++ b/tests/end-to-end/api/05-chat.js
@@ -363,8 +363,22 @@ describe('[Chat]', function() {
 				.end(done);
 		});
 	});
-
-	describe('/chat.react', () => {
+	describe('[/chat.react]', () => {
+		it('should return statusCode: 200 and success when try unreact a message that\'s no reacted yet', (done) => {
+			request.post(api('chat.react'))
+				.set(credentials)
+				.send({
+					emoji: ':squid:',
+					messageId: message._id,
+					shouldReact: false
+				})
+				.expect('Content-Type', 'application/json')
+				.expect(200)
+				.expect((res) => {
+					expect(res.body).to.have.property('success', true);
+				})
+				.end(done);
+		});
 		it('should react a message successfully', (done) => {
 			request.post(api('chat.react'))
 				.set(credentials)
@@ -394,7 +408,51 @@ describe('[Chat]', function() {
 				})
 				.end(done);
 		});
-
+		it('should return statusCode: 200 and success when try react a message that\'s already reacted', (done) => {
+			request.post(api('chat.react'))
+				.set(credentials)
+				.send({
+					emoji: ':squid:',
+					messageId: message._id,
+					shouldReact: true
+				})
+				.expect('Content-Type', 'application/json')
+				.expect(200)
+				.expect((res) => {
+					expect(res.body).to.have.property('success', true);
+				})
+				.end(done);
+		});
+		it('should return statusCode: 200 when unreact a message with flag, shouldReact: false', (done) => {
+			request.post(api('chat.react'))
+				.set(credentials)
+				.send({
+					emoji: ':squid:',
+					messageId: message._id,
+					shouldReact: false
+				})
+				.expect('Content-Type', 'application/json')
+				.expect(200)
+				.expect((res) => {
+					expect(res.body).to.have.property('success', true);
+				})
+				.end(done);
+		});
+		it('should return statusCode: 200 when react a message with flag, shouldReact: true', (done) => {
+			request.post(api('chat.react'))
+				.set(credentials)
+				.send({
+					emoji: ':squid:',
+					messageId: message._id,
+					shouldReact: true
+				})
+				.expect('Content-Type', 'application/json')
+				.expect(200)
+				.expect((res) => {
+					expect(res.body).to.have.property('success', true);
+				})
+				.end(done);
+		});
 		it('should return statusCode: 200 when the emoji is valid and has no colons', (done) => {
 			request.post(api('chat.react'))
 				.set(credentials)
@@ -409,7 +467,6 @@ describe('[Chat]', function() {
 				})
 				.end(done);
 		});
-
 		it('should return statusCode: 200 for reaction property when the emoji is valid', (done) => {
 			request.post(api('chat.react'))
 				.set(credentials)