diff --git a/README.md b/README.md
index 2ecd1072..8d68254a 100644
--- a/README.md
+++ b/README.md
@@ -93,7 +93,7 @@ high quality
 image](https://github.com/google/guetzli/releases/download/v0/bees.png).
 
 You can pass a `--quality Q` parameter to set quality in units equivalent to
-libjpeg quality. You can also pass a `--verbose` flag to see a trace of encoding
+libjpeg quality (minimal quality value for guetzli is `84`). You can also pass a `--verbose` flag to see a trace of encoding
 attempts made.
 
 Please note that JPEG images do not support alpha channel (transparency). If the