diff --git a/lib/timers.js b/lib/timers.js
index 478a05433912f3..dc2506e01e09a4 100644
--- a/lib/timers.js
+++ b/lib/timers.js
@@ -100,7 +100,7 @@ const unrefedLists = {};
 
 // Schedule or re-schedule a timer.
 // The item must have been enroll()'d first.
-exports.active = function(item) {
+const active = exports.active = function(item) {
   insert(item, false);
 };
 
@@ -351,19 +351,19 @@ exports.setTimeout = function(callback, after) {
 
   if (process.domain) timer.domain = process.domain;
 
-  exports.active(timer);
+  active(timer);
 
   return timer;
 };
 
 
-exports.clearTimeout = function(timer) {
+const clearTimeout = exports.clearTimeout = function(timer) {
   if (timer && (timer[kOnTimeout] || timer._onTimeout)) {
     timer[kOnTimeout] = timer._onTimeout = null;
     if (timer instanceof Timeout) {
       timer.close(); // for after === 0
     } else {
-      exports.unenroll(timer);
+      unenroll(timer);
     }
   }
 };
@@ -409,7 +409,7 @@ exports.setInterval = function(callback, repeat) {
   timer._repeat = ontimeout;
 
   if (process.domain) timer.domain = process.domain;
-  exports.active(timer);
+  active(timer);
 
   return timer;
 
@@ -425,7 +425,7 @@ exports.setInterval = function(callback, repeat) {
       this._handle.start(repeat, 0);
     } else {
       timer._idleTimeout = repeat;
-      exports.active(timer);
+      active(timer);
     }
   }
 };
@@ -468,7 +468,7 @@ Timeout.prototype.unref = function() {
 
     // Prevent running cb again when unref() is called during the same cb
     if (this._called && !this._repeat) {
-      exports.unenroll(this);
+      unenroll(this);
       return;
     }
 
@@ -496,7 +496,7 @@ Timeout.prototype.close = function() {
     this._handle[kOnTimeout] = null;
     this._handle.close();
   } else {
-    exports.unenroll(this);
+    unenroll(this);
   }
   return this;
 };
diff --git a/test/parallel/test-timers-api-refs.js b/test/parallel/test-timers-api-refs.js
new file mode 100644
index 00000000000000..c062369444b1e0
--- /dev/null
+++ b/test/parallel/test-timers-api-refs.js
@@ -0,0 +1,21 @@
+'use strict';
+const common = require('../common');
+const timers = require('timers');
+
+// delete global APIs to make sure they're not relied on by the internal timers
+// code
+delete global.setTimeout;
+delete global.clearTimeout;
+delete global.setInterval;
+delete global.clearInterval;
+delete global.setImmediate;
+delete global.clearImmediate;
+
+const timeoutCallback = () => { timers.clearTimeout(timeout); };
+const timeout = timers.setTimeout(common.mustCall(timeoutCallback), 1);
+
+const intervalCallback = () => { timers.clearInterval(interval); };
+const interval = timers.setInterval(common.mustCall(intervalCallback), 1);
+
+const immediateCallback = () => { timers.clearImmediate(immediate); };
+const immediate = timers.setImmediate(immediateCallback);