diff --git a/README.md b/README.md
index fb21bae..c697147 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,6 @@
+# dev
+This is the **development branch** of tinybvh.
+
 # tinybvh
 Single-header BVH construction and traversal library written as "Sane C++" (or "C with classes"). Some C++11 is used, e.g. for threading. The library has no dependencies.