diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index be3312c..24d4963 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -109,7 +109,7 @@ jobs:
   compatibility-test:
     strategy:
       matrix:
-        go-version: ["1.20", "1.19"]
+        go-version: ["1.21", "1.20", "1.19"]
         os: [ubuntu-latest, macos-latest, windows-latest]
         # GitHub Actions does not support arm* architectures on default
         # runners. It is possible to acomplish this with a self-hosted runner
diff --git a/CHANGELOG.md b/CHANGELOG.md
index df8844d..771e289 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Added
 
 - `SpanFilter` configuration in `SpanOptions` to filter spans creation. (#174)
+- Go 1.21 to supported versions. (#180)
 
 ## [0.23.0] - 2023-05-22
 
diff --git a/README.md b/README.md
index 4f57dbf..f8eb62f 100644
--- a/README.md
+++ b/README.md
@@ -70,14 +70,19 @@ This project is tested on the following systems.
 
 | OS      | Go Version | Architecture |
 | ------- | ---------- | ------------ |
+| Ubuntu  | 1.21       | amd64        |
 | Ubuntu  | 1.20       | amd64        |
 | Ubuntu  | 1.19       | amd64        |
+| Ubuntu  | 1.21       | 386          |
 | Ubuntu  | 1.20       | 386          |
 | Ubuntu  | 1.19       | 386          |
+| MacOS   | 1.21       | amd64        |
 | MacOS   | 1.20       | amd64        |
 | MacOS   | 1.19       | amd64        |
+| Windows | 1.21       | amd64        |
 | Windows | 1.20       | amd64        |
 | Windows | 1.19       | amd64        |
+| Windows | 1.21       | 386          |
 | Windows | 1.20       | 386          |
 | Windows | 1.19       | 386          |