diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 646ab9d..3a21036 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: "25.3.0"
+          node-version: "26"
           cache: "npm"
           registry-url: "https://registry.npmjs.org"
 
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 7ca520a..26c3e00 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -34,7 +34,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: "25.3.0"
+          node-version: "26"
           cache: "npm"
           registry-url: "https://registry.npmjs.org"
 
diff --git a/CLAUDE.md b/CLAUDE.md
index 120b76c..ed6fa69 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -63,4 +63,4 @@ Tests use Vitest with in-memory mocks. Key patterns:
 - Vite for bundling (`vite.config.ts`)
 - vite-plugin-dts for TypeScript declarations
 - ESM-only output (`"type": "module"`)
-- Node.js >= 25.3.0 required
+- Node.js >= 25.3.0 required (`engines`). CI and the release workflow run on Node 26, because vitest 5 supports `^22.12 || ^24 || >=26` and not Node 25