diff --git a/src/node/server.js b/src/node/server.js
index a6ddc4039..6d1351520 100755
--- a/src/node/server.js
+++ b/src/node/server.js
@@ -50,6 +50,7 @@ const express = require('./hooks/express');
 const hooks = require('../static/js/pluginfw/hooks');
 const pluginDefs = require('../static/js/pluginfw/plugin_defs');
 const plugins = require('../static/js/pluginfw/plugins');
+const {Gate} = require('./utils/promises');
 const stats = require('./stats');
 
 const logger = log4js.getLogger('server');
@@ -67,14 +68,6 @@ const State = {
 
 let state = State.INITIAL;
 
-class Gate extends Promise {
-  constructor(executor = null) {
-    let res;
-    super((resolve, reject) => { res = resolve; if (executor != null) executor(resolve, reject); });
-    this.resolve = res;
-  }
-}
-
 const removeSignalListener = (signal, listener) => {
   logger.debug(`Removing ${signal} listener because it might interfere with shutdown tasks. ` +
                `Function code:\n${listener.toString()}\n` +
diff --git a/src/node/utils/promises.js b/src/node/utils/promises.js
index 0c8dc24f3..b9529d305 100644
--- a/src/node/utils/promises.js
+++ b/src/node/utils/promises.js
@@ -54,3 +54,15 @@ exports.timesLimit = async (total, concurrency, promiseCreator) => {
   }
   await Promise.all(promises);
 };
+
+/**
+ * An ordinary Promise except the `resolve` executor function is exposed as a property.
+ */
+class Gate extends Promise {
+  constructor(executor = null) {
+    let res;
+    super((resolve, reject) => { res = resolve; if (executor != null) executor(resolve, reject); });
+    this.resolve = res;
+  }
+}
+exports.Gate = Gate;