diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 47d9c80..7560b16 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -28,7 +28,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby_version: ['3.3', 'head']
+        ruby_version: ['3.3']
         os: [ubuntu-latest]
     env:
       BUNDLE_RETRY: 3
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c5f88b3..938d5fe 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 ## Changed
 - Updated development dependencies (`armitage-rubocop`);
 - Constant renaming: all constants and constant parts were renamed from `Acquier` to `Acquirer`;
+- CI is splitted to "mainstream ruby version" and "previous actually maintaned ruby versions";
 ## Added
 - Type signatures (`RBS`, see the `sig` directory) + `Steep` integration (see `Steepfile` for details);