diff --git a/README.md b/README.md
index b6abc379..1df4c2b8 100644
--- a/README.md
+++ b/README.md
@@ -354,6 +354,9 @@ to set `true`; it's effectively a shortcut for `foo=true`).
   compressor from mangling/discarding function names.  Useful for code relying on
   `Function.prototype.name`.
 
+- `ascii-only` (default `false`) -- escape Unicode characters in strings and
+  regexps
+
 
 ### The `unsafe` option