diff --git a/metro/metrics-collector.js b/metro/metrics-collector.js
index 50ef3cd5..bf488c17 100644
--- a/metro/metrics-collector.js
+++ b/metro/metrics-collector.js
@@ -115,4 +115,5 @@ http
         res.writeHead(200, { 'Content-Type': register.contentType });
         res.end(register.metrics());
     })
-    .listen(port);
+    .listen(port)
+    .unref();