diff --git a/docs/reference/builder.md b/docs/reference/builder.md
index 6ec9e7d1c6..3a73b87d29 100644
--- a/docs/reference/builder.md
+++ b/docs/reference/builder.md
@@ -949,6 +949,7 @@ For example:
 
     ENV DIRPATH /path
     WORKDIR $DIRPATH/$DIRNAME
+    RUN pwd
 
 The output of the final `pwd` command in this `Dockerfile` would be
 `/path/$DIRNAME`