diff --git a/doc/api/timers.md b/doc/api/timers.md
index 71079343db3aad..ed200f3c36e701 100644
--- a/doc/api/timers.md
+++ b/doc/api/timers.md
@@ -305,7 +305,8 @@ Cancels an `Immediate` object created by [`setImmediate()`][].
 added: v0.0.1
 -->
 
-* `timeout` {Timeout} A `Timeout` object as returned by [`setInterval()`][].
+* `timeout` {Timeout|string|number} A `Timeout` object as returned by [`setInterval()`][]
+  or the [primitive][] of the `Timeout` object as a string or a number.
 
 Cancels a `Timeout` object created by [`setInterval()`][].
 
@@ -314,7 +315,8 @@ Cancels a `Timeout` object created by [`setInterval()`][].
 added: v0.0.1
 -->
 
-* `timeout` {Timeout} A `Timeout` object as returned by [`setTimeout()`][].
+* `timeout` {Timeout|string|number} A `Timeout` object as returned by [`setTimeout()`][]
+  or the [primitive][] of the `Timeout` object as a string or a number.
 
 Cancels a `Timeout` object created by [`setTimeout()`][].
 
@@ -329,3 +331,4 @@ Cancels a `Timeout` object created by [`setTimeout()`][].
 [`setTimeout()`]: timers.md#timers_settimeout_callback_delay_args
 [`util.promisify()`]: util.md#util_util_promisify_original
 [`worker_threads`]: worker_threads.md
+[primitive]: timers.md#timers_timeout_symbol_toprimitive