diff --git a/README.md b/README.md
index 5e487042..b84d40d1 100644
--- a/README.md
+++ b/README.md
@@ -56,6 +56,9 @@ NOTE: This library as of now compiles correctly only with gcc-9.1 and newer.
 
 ## Release notes
 
+- 0.4.0 ???
+  - 
+
 - 0.3.1 Sep 18, 2019
   - cmcstl2 dependency changed to range-v3 0.9.1
 
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 7e8e8b0b..f6bd63ce 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -24,7 +24,7 @@ cmake_minimum_required(VERSION 3.8)
 #cmake_policy(SET CMP0076 NEW)
 
 project(units
-    VERSION 0.3.0
+    VERSION 0.4.0
     LANGUAGES CXX
 )