diff --git a/doc/api/errors.md b/doc/api/errors.md
index 131d223f66867a..c21ae1940fbc4a 100644
--- a/doc/api/errors.md
+++ b/doc/api/errors.md
@@ -1674,6 +1674,16 @@ category.
 The `trace_events` module could not be loaded because Node.js was compiled with
 the `--without-v8-platform` flag.
 
+<a id="ERR_TRANSFERRING_EXTERNALIZED_SHAREDARRAYBUFFER"></a>
+### ERR_TRANSFERRING_EXTERNALIZED_SHAREDARRAYBUFFER
+
+A `SharedArrayBuffer` whose memory is not managed by the JavaScript engine
+or by Node.js was encountered during serialization. Such a `SharedArrayBuffer`
+cannot be serialized.
+
+This can only happen when native addons create `SharedArrayBuffer`s in
+"externalized" mode, or put existing `SharedArrayBuffer` into externalized mode.
+
 <a id="ERR_TRANSFORM_ALREADY_TRANSFORMING"></a>
 ### ERR_TRANSFORM_ALREADY_TRANSFORMING