diff --git a/CHANGES b/CHANGES
index 17322977be..9e28a020e4 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,8 @@ Revision history for SPIRV-Tools
 v2017.1-dev 2017-09-01
  - Validator:
    - Type check basic arithmetic operations
+   - OpModuleProcessed is only allowed after debug names section and before annotations
+     section.
  - Fixes:
    #798: spirv-as should fail when given unrecognized long option
    #800: Inliner: Fix inlining function into header of multi-block loop