diff --git a/docker/frontend/nginx.conf b/docker/frontend/nginx.conf
index af4ca85f2..b8521eb5b 100644
--- a/docker/frontend/nginx.conf
+++ b/docker/frontend/nginx.conf
@@ -90,6 +90,13 @@ http {
             proxy_set_header X-Forwarded-Port $server_port;
         }
 
+        # Serve .mjs files with correct MIME type
+        location ~* \.mjs$ {
+            add_header Content-Type text/javascript;
+            expires 1y;
+            add_header Cache-Control "public, immutable";
+        }
+
         # Cache static assets
         location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
             expires 1y;