diff --git a/Dockerfile b/Dockerfile
index c869a1b..7ac0e18 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -18,4 +18,6 @@ RUN cd /home/node/app/node_api/api && npm install -D --force
 RUN cd /home/node/app/node_api/web && npm install -D --force
 RUN cd /home/node/app/node_api/web && npm run build
 
-CMD ["NODE_ENV=production", "node", "/home/node/app/node_api/api/index.js"]
+# set to production
+ENV NODE_ENV=production
+CMD ["node", "/home/node/app/node_api/api/index.js"]
diff --git a/node_api/api/index.js b/node_api/api/index.js
index 10f29c3..c865ac6 100644
--- a/node_api/api/index.js
+++ b/node_api/api/index.js
@@ -81,7 +81,7 @@ async function fetchTTSAudioURL(req, phrase, phraseId) {
 		await synthesizePollyVoice(phrase, phraseId)
 	}
 
-	return `${NODE_ENV === "production" ? "https" : req.protocol}://${req.get("host")}${req.path}/audio/${phraseId}.mp3`
+	return `${process.env.NODE_ENV === "production" ? "https" : req.protocol}://${req.get("host")}${req.path}/audio/${phraseId}.mp3`
 }
 
 async function handleApiRequest(req, res) {