diff --git a/src/config.coffee b/src/config.coffee
index 617711bb..2447a7e7 100644
--- a/src/config.coffee
+++ b/src/config.coffee
@@ -4,5 +4,14 @@ module.exports = config =
 	pubnub:
 		subscribe_key: process.env.PUBNUB_SUBSCRIBE_KEY
 		publish_key: process.env.PUBNUB_PUBLISH_KEY
+	expectedEnvVars: [
+		'API_ENDPOINT'
+		'REGISTRY_ENDPOINT'
+		'PUBNUB_SUBSCRIBE_KEY'
+		'PUBNUB_PUBLISH_KEY'
+	]
+
+# A check that all variables are set and notify the user if not
+for envVar in config.expectedEnvVars when !process.env[envVar]?
+	console.error('Cannot find env var:', envVar)
 
-# TODO add a check that all variables are set and notify the user if not
diff --git a/src/supervisor-update.coffee b/src/supervisor-update.coffee
index b85c0343..4f6abb9c 100644
--- a/src/supervisor-update.coffee
+++ b/src/supervisor-update.coffee
@@ -12,7 +12,7 @@ Promise.promisifyAll(docker.getImage().__proto__)
 Promise.promisifyAll(docker.getContainer().__proto__)
 
 localImage = 'resin/rpi-supervisor'
-remoteImage = config.REGISTRY_ENDPOINT + '/' + localImage
+remoteImage = config.registryEndpoint + '/' + localImage
 
 supervisorUpdating = Promise.resolve()
 exports.update = ->
@@ -44,10 +44,9 @@ exports.update = ->
 				'/boot/config.json': '/mnt/mmcblk0p1/config.json'
 				'/data': '/var/lib/docker/data'
 				'/run/docker.sock': '/var/run/docker.sock'
-			Env: [
-				'API_ENDPOINT=' + config.API_ENDPOINT
-				'REGISTRY_ENDPOINT=' + config.REGISTRY_ENDPOINT
-			]
+			Env:
+				for envVar in config.expectedEnvVars
+					envVar + '=' + process.env[envVar]
 		)
 	.then (container) ->
 		console.log('Starting updated supervisor container:', localImage)