diff --git a/doc/api/child_process.markdown b/doc/api/child_process.markdown
index 85c9c8b8d4..4dfa7d8c6c 100644
--- a/doc/api/child_process.markdown
+++ b/doc/api/child_process.markdown
@@ -225,7 +225,7 @@ that some connections will be handled by the parent and some by the child.
 
 For `dgram` servers the workflow is exactly the same.  Here you listen on
 a `message` event instead of `connection` and use `server.bind` instead of
-`server.listen`.
+`server.listen`.  (Currently only supported on UNIX platforms.)
 
 #### Example: sending socket object