Start SPIRV-Tools v2021.3
diff --git a/CHANGES b/CHANGES
index b154b9b..467655c 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,5 +1,8 @@
 Revision history for SPIRV-Tools
 
+v2021.3-dev 2021-06-22
+ - Start v2021.3-dev
+
 v2021.2 2021-06-18
  - General
     - Support SPV_KHR_subgroup_uniform_control_flow (#4318)