diff --git a/docs/reference/builder.md b/docs/reference/builder.md
index ce14b741c3..7e73282a7c 100644
--- a/docs/reference/builder.md
+++ b/docs/reference/builder.md
@@ -1824,6 +1824,11 @@ RUN pwd
 The output of the final `pwd` command in this `Dockerfile` would be
 `/path/$DIRNAME`
 
+If not specified, the default working directory is `/`. In practice, if you aren't building a Dockerfile from scratch (`FROM scratch`), 
+the `WORKDIR` may likely be set by the base image you're using.
+
+Therefore, to avoid unintended operations in unknown directories, it is best practice to set your `WORKDIR` explicitly.
+
 ## ARG
 
 ```dockerfile