diff --git a/doc/api/assert.md b/doc/api/assert.md
index c3735440932e25..9a37d5f26c1e9b 100644
--- a/doc/api/assert.md
+++ b/doc/api/assert.md
@@ -442,6 +442,8 @@ argument in callbacks.
 ```js
 const assert = require('assert').strict;
 
+assert.ifError(null);
+// OK
 assert.ifError(0);
 // OK
 assert.ifError(1);