diff --git a/lib/timers.js b/lib/timers.js
index 6651e24a4e..7bfed79d15 100644
--- a/lib/timers.js
+++ b/lib/timers.js
@@ -598,6 +598,9 @@ Timeout.prototype.unref = function() {
     }
 
     var handle = reuse(this);
+    if (handle) {
+      handle._list = undefined;
+    }
 
     this._handle = handle || new TimerWrap();
     this._handle.owner = this;
diff --git a/test/parallel/test-timers-unref-reuse-no-exposed-list.js b/test/parallel/test-timers-unref-reuse-no-exposed-list.js
new file mode 100644
index 0000000000..33b2da2f9e
--- /dev/null
+++ b/test/parallel/test-timers-unref-reuse-no-exposed-list.js
@@ -0,0 +1,14 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+
+const timer1 = setTimeout(() => {}, 1).unref();
+assert.strictEqual(timer1._handle._list, undefined,
+                   'timer1._handle._list should be undefined');
+
+// Check that everything works even if the handle was not re-used.
+setTimeout(() => {}, 1);
+const timer2 = setTimeout(() => {}, 1).unref();
+assert.strictEqual(timer2._handle._list, undefined,
+                   'timer2._handle._list should be undefined');