diff --git a/README.md b/README.md
index 4722e710..1015c813 100644
--- a/README.md
+++ b/README.md
@@ -9,6 +9,13 @@ More info at https://phoboslab.org/log/2021/11/qoi-fast-lossless-image-compressi
 
 ⚠️ Please note that this library is not yet ready to deal with untrusted input.
 
+⚠️ 2021.11.27 – the specification for QOI has changed to accomodate some 
+concerns with the format. These specification changes are **not yet reflected in
+the code here**. If you are working on a QOI implementation, please refer to 
+[#37 The QOI File Format Specification](https://github.com/phoboslab/qoi/issues/37) 
+for the details.
+
+
 ## Why?
 
 Compared to stb_image and stb_image_write QOI offers 20x-50x faster encoding,