diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index aec3da08..6665c1a8 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -10,7 +10,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-20.04, ubuntu-22.04, ubuntu-24.04, macos-12, macos-arm-oss ]
+        os: [ ubuntu-20.04, ubuntu-22.04, ubuntu-24.04, macos-12, macos-14 ]
         ruby: [jruby-9.4.8.0]
     runs-on: ${{ matrix.os }}
     steps:
@@ -25,7 +25,7 @@ jobs:
       run: |
         platform=${{ matrix.os }}
         platform=${platform/macos-12/macos-latest}
-        platform=${platform/macos-arm-oss/macos-13-arm64}
+        platform=${platform/macos-14/macos-13-arm64}
         echo "platform=$platform" >> $GITHUB_OUTPUT
     - name: Set ruby
       id: ruby
@@ -95,7 +95,7 @@ jobs:
     # https://github.com/rbenv/ruby-build/discussions/1961#discussioncomment-4031745
     - name: Override RUBY_CONFIGURE_OPTS if macos-arm64 ruby-3.1
       run: echo 'RUBY_CONFIGURE_OPTS=--disable-shared --disable-install-doc' >> $GITHUB_ENV
-      if: matrix.os == 'macos-arm-oss' && startsWith(steps.ruby.outputs.ruby, 'ruby-3.1')
+      if: matrix.os == 'macos-14' && startsWith(steps.ruby.outputs.ruby, 'ruby-3.1')
 
     - name: Build Ruby
       run: ruby-build --verbose $RUBY_BUILD_RUBY_NAME $PREFIX
diff --git a/README.md b/README.md
index ff819ebb..72a480ce 100644
--- a/README.md
+++ b/README.md
@@ -30,8 +30,8 @@ Archives are named `$engine-$version-$platform.tar.gz`.
 
 `platform` is one of:
 * `ubuntu-NN.NN`: built on the corresponding GitHub-hosted runner virtual environment
-* `macos-latest`: built on `macos-12` (the oldest `macos` available on GitHub-hosted runners)
-* `macos-13-arm64`: built on `macos-arm-oss`
+* `macos-latest`: built on `macos-12`, the oldest `macos-amd64` available on GitHub-hosted runners.
+* `macos-13-arm64`: built on `macos-14`, the oldest `macos-arm64` available on GitHub-hosted runners.
 * `windows-latest`: built on `windows-2019` (does not matter, it's only for repacking a JRuby archive, no actual build)
 
 The names contain `-latest` for compatibility, even though what `-latest` points to for runners might have changed.