diff --git a/src/docker.js b/src/docker.js
index 3a9cfa2c5..a7001932e 100644
--- a/src/docker.js
+++ b/src/docker.js
@@ -277,6 +277,8 @@ async function createSubcontainer(app, name, cmd, options) {
         `CLOUDRON_APP_DOMAIN=${domain}`
     ];
 
+    if (app.manifest.multiDomain) stdEnv.push(`CLOUDRON_ALIAS_DOMAINS=${app.aliasDomains.map(ad => ad.fqdn).join(',')}`);
+
     const secondaryDomainsEnv = app.secondaryDomains.map(sd => `${sd.environmentVariable}=${sd.fqdn}`);
 
     const portEnv = [];