diff --git a/docs/api-output.md b/docs/api-output.md
index 04464cb0..63a2cfea 100644
--- a/docs/api-output.md
+++ b/docs/api-output.md
@@ -11,6 +11,8 @@ Note that raw pixel data is only supported for buffer output.
 By default all metadata will be removed, which includes EXIF-based orientation.
 See [withMetadata][1] for control over this.
 
+The caller is responsible for ensuring directory structures and permissions exist.
+
 A `Promise` is returned when `callback` is not provided.
 
 ### Parameters
diff --git a/lib/output.js b/lib/output.js
index a57e09f5..6ec1b125 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -28,6 +28,8 @@ const errMagickSave = new Error('GIF output requires libvips with support for Im
  * By default all metadata will be removed, which includes EXIF-based orientation.
  * See {@link withMetadata} for control over this.
  *
+ * The caller is responsible for ensuring directory structures and permissions exist.
+ *
  * A `Promise` is returned when `callback` is not provided.
  *
  * @example