diff --git a/packages/rocketchat-lib/lib/slashCommand.coffee b/packages/rocketchat-lib/lib/slashCommand.coffee
index 0fad4644a4f0..8e8b7b4ee701 100644
--- a/packages/rocketchat-lib/lib/slashCommand.coffee
+++ b/packages/rocketchat-lib/lib/slashCommand.coffee
@@ -1,14 +1,14 @@
 RocketChat.slashCommands =
 	commands: {}
 
-RocketChat.slashCommands.add = (command, callback, options) ->
+RocketChat.slashCommands.add = (command, callback, options, result) ->
 	RocketChat.slashCommands.commands[command] =
 		command: command
 		callback: callback
 		params: options?.params
 		description: options?.description
 		clientOnly: options?.clientOnly or false
-
+		result: result
 	return
 
 RocketChat.slashCommands.run = (command, params, item) ->
diff --git a/packages/rocketchat-slashcommands-join/client.coffee b/packages/rocketchat-slashcommands-join/client.coffee
index 922aeedc74c7..92ede9a683a7 100644
--- a/packages/rocketchat-slashcommands-join/client.coffee
+++ b/packages/rocketchat-slashcommands-join/client.coffee
@@ -1,3 +1,8 @@
 RocketChat.slashCommands.add 'join', undefined,
-	description: 'Join_the_given_channel'
-	params: '#channel'
+		description: 'Join_the_given_channel'
+		params: '#channel'
+	(err, result, params) -> 
+		if err.error == 'error-user-already-in-room'
+			params.cmd = 'open'
+			params.msg.msg = params.msg.msg.replace('join', 'open')
+			RocketChat.slashCommands.run 'open', params.params, params.msg
\ No newline at end of file
diff --git a/packages/rocketchat-slashcommands-join/server.coffee b/packages/rocketchat-slashcommands-join/server.coffee
index bf66a39d62d8..c6bebe71cf8d 100644
--- a/packages/rocketchat-slashcommands-join/server.coffee
+++ b/packages/rocketchat-slashcommands-join/server.coffee
@@ -15,17 +15,19 @@ class Join
 		channel = channel.replace('#', '')
 
 		user = Meteor.users.findOne Meteor.userId()
-		room = RocketChat.models.Rooms.findOneByNameAndTypeNotContainingUsername(channel, 'c', user.username)
-
-		if not room?
-			RocketChat.Notifications.notifyUser Meteor.userId(), 'message', {
+		room = RocketChat.models.Rooms.findOneByNameAndType channel, 'c'
+		
+		if not room
+			RocketChat.Notifications.notifyUser Meteor.userId(), 'message',
 				_id: Random.id()
 				rid: item.rid
 				ts: new Date
 				msg: TAPi18n.__('Channel_doesnt_exist', { postProcess: 'sprintf', sprintf: [ channel ] }, user.language)
-			}
-			return
-
+			
+		throw new Meteor.Error('error-user-already-in-room', 'You are already in the channel', {
+			method: 'slashCommands'
+		}) if room.usernames.indexOf(user.username) > -1
+		
 		Meteor.call 'joinRoom', room._id
 
 RocketChat.slashCommands.add 'join', Join
diff --git a/packages/rocketchat-ui/client/lib/chatMessages.coffee b/packages/rocketchat-ui/client/lib/chatMessages.coffee
index 2b22a3b5f379..aa4bd9276bc8 100644
--- a/packages/rocketchat-ui/client/lib/chatMessages.coffee
+++ b/packages/rocketchat-ui/client/lib/chatMessages.coffee
@@ -189,7 +189,7 @@ class @ChatMessages
 							if commandOptions.clientOnly
 								commandOptions.callback(command, param, msgObject)
 							else
-								Meteor.call 'slashCommand', {cmd: command, params: param, msg: msgObject }
+								Meteor.call 'slashCommand', {cmd: command, params: param, msg: msgObject }, (err, result) -> commandOptions.result?(err, result, {cmd: command, params: param, msg: msgObject })
 							return
 
 						if !RocketChat.settings.get('Message_AllowUnrecognizedSlashCommand')