diff --git a/content/api/node.md b/content/api/node.md
index 86bc2ebbc1ab..c1de9477082d 100644
--- a/content/api/node.md
+++ b/content/api/node.md
@@ -277,4 +277,4 @@ compiler.run((err, stats) => {
 });
 ```
 
-T> The output file system you provide needs to be compatible with Node’s own [`fs`](https://nodejs.org/api/fs.html) module interface.
+T> The output file system you provide needs to be compatible with Node’s own [`fs`](https://nodejs.org/api/fs.html) module interface, which requires the `mkdirp` and `join` helper methods.