diff --git a/components/engine/docs/reference/builder.md b/components/engine/docs/reference/builder.md
index 537cc98ece..29c1153f87 100644
--- a/components/engine/docs/reference/builder.md
+++ b/components/engine/docs/reference/builder.md
@@ -155,6 +155,7 @@ the `Dockerfile`:
 * `COPY`
 * `ENV`
 * `EXPOSE`
+* `LABEL`
 * `USER`
 * `WORKDIR`
 * `VOLUME`