diff --git a/.github/workflows/arch-qemu-nightly.yml b/.github/workflows/arch-qemu-nightly.yml
index c172c348..fd29a6a0 100644
--- a/.github/workflows/arch-qemu-nightly.yml
+++ b/.github/workflows/arch-qemu-nightly.yml
@@ -43,7 +43,7 @@ jobs:
       - uses: actions/checkout@v7
       - uses: actions/setup-go@v7
         with:
-          go-version: stable
+          go-version: 1.27.1
       # This has not hung here. It hung in go-crdt/crdt, on the same runner
       # image and the same one-line install, for the better part of an hour and
       # more than once — and bounding it is what identified the culprit: three
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0b3d1aa4..aa659bcc 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -30,7 +30,7 @@ jobs:
       - uses: actions/checkout@v7
       - uses: actions/setup-go@v7
         with:
-          go-version: stable
+          go-version: 1.27.1
       - run: go version
       - run: go vet ./...
       - run: go build ./...
@@ -106,7 +106,7 @@ jobs:
       - uses: actions/checkout@v7
       - uses: actions/setup-go@v7
         with:
-          go-version: stable
+          go-version: 1.27.1
       - run: go env GOARCH && go test ./...
 
   # WebAssembly (WASI preview 1) gate: the same interpreter compiled for
@@ -123,7 +123,7 @@ jobs:
       - uses: actions/checkout@v7
       - uses: actions/setup-go@v7
         with:
-          go-version: stable
+          go-version: 1.27.1
       - run: go version
       - name: Build rbgo.wasm (CGO=0, GOOS=wasip1)
         run: CGO_ENABLED=0 GOOS=wasip1 GOARCH=wasm go build -o rbgo.wasm ./cmd/rbgo
@@ -175,7 +175,7 @@ jobs:
       - uses: actions/checkout@v7
       - uses: actions/setup-go@v7
         with:
-          go-version: stable
+          go-version: 1.27.1
       - uses: actions/setup-node@v7
         with:
           node-version: '24'
@@ -246,7 +246,7 @@ jobs:
       - uses: actions/checkout@v7
       - uses: actions/setup-go@v7
         with:
-          go-version: stable
+          go-version: 1.27.1
       - uses: actions/setup-node@v7
         with:
           node-version: '24'
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 6c9e772d..d7e34056 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -46,7 +46,7 @@ jobs:
       - uses: actions/checkout@v7
       - uses: actions/setup-go@v7
         with:
-          go-version: stable
+          go-version: 1.27.1
       - name: Build rbgo-${{ matrix.goos }}-${{ matrix.goarch }}${{ matrix.ext }}
         env:
           CGO_ENABLED: '0'
diff --git a/.github/workflows/rubyspec-ratchet.yml b/.github/workflows/rubyspec-ratchet.yml
index 5de2f411..12ea58db 100644
--- a/.github/workflows/rubyspec-ratchet.yml
+++ b/.github/workflows/rubyspec-ratchet.yml
@@ -23,7 +23,7 @@ jobs:
       - uses: actions/checkout@v7
       - uses: actions/setup-go@v7
         with:
-          go-version: stable
+          go-version: 1.27.1
       - run: go version
       - name: What the runner has to start with
         run: |
diff --git a/go.mod b/go.mod
index 98b3dc20..324d59c8 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/go-embedded-ruby/ruby
 
-go 1.26.6
+go 1.27.1
 
 require (
 	github.com/alicebob/miniredis/v2 v2.39.0