diff --git a/CHANGELOG.md b/CHANGELOG.md
index 517e63ac1f1..97339f5c48f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -32,6 +32,8 @@ release.
 
 - Define file configuration parse and create operations.
   ([#3437](https://github.com/open-telemetry/opentelemetry-specification/pull/3437))
+- Add environment variable implementation guidelines.
+  ([#3738](https://github.com/open-telemetry/opentelemetry-specification/pull/3738))
 
 ### Common