diff --git a/packages/server/src/api.ts b/packages/server/src/api.ts
index 2f4628b..9abf7b2 100644
--- a/packages/server/src/api.ts
+++ b/packages/server/src/api.ts
@@ -67,7 +67,7 @@ export default function(fastify: FastifyInstance, opts, done) {
 
       reply.headers({
         "Content-Type": "application/sdp",
-        "Location": `${opts.instance.getServerAddress()}${opts.prefix}/whip/${type}/${resource.getId()}`,
+        "Location": `${opts.instance.getServerAddress()||''}${opts.prefix}/whip/${type}/${resource.getId()}`,
       });
       const links = addIceLinks(resource.getIceServers(), request.headers["authorization"])
         .concat(addProtocolExtensions(resource));
diff --git a/packages/server/src/index.ts b/packages/server/src/index.ts
index 2aad655..5647e89 100644
--- a/packages/server/src/index.ts
+++ b/packages/server/src/index.ts
@@ -40,7 +40,7 @@ export class WHIPEndpoint {
     this.extPort = opts?.extPort || this.port;
     this.interfaceIp = opts?.interfaceIp || "0.0.0.0";
     this.useHttps = !!(opts?.https);
-    this.hostname = opts?.hostname || "localhost";
+    this.hostname = opts?.hostname;
     this.enabledWrtcPlugins = opts?.enabledWrtcPlugins || [];
     this.iceServers = opts?.iceServers || [];
     this.tls = opts?.tls;
@@ -118,8 +118,11 @@ export class WHIPEndpoint {
     return this.iceServers;
   }
 
-  getServerAddress(): string {
-    return (this.useHttps ? "https" : "http") + "://" + this.hostname + ":" + this.extPort;
+  getServerAddress(): string | undefined {
+    if (this.hostname) {
+      return (this.useHttps ? "https" : "http") + "://" + this.hostname + ":" + this.extPort;
+    }
+    return undefined;
   }
 
   listen() {