diff --git a/.github/workflows/validate.yml b/.github/workflows/validate.yml
index 473019c..93ff9b2 100644
--- a/.github/workflows/validate.yml
+++ b/.github/workflows/validate.yml
@@ -21,6 +21,9 @@ jobs:
         with:
           node-version: 20.x
 
+      - name: Set up pnpm
+        run: corepack enable pnpm && corepack install
+
       - name: Install dependencies
         run: pnpm install --offline
 
diff --git a/package.json b/package.json
index 2342aac..c1018ca 100644
--- a/package.json
+++ b/package.json
@@ -15,5 +15,6 @@
     "test:default": "RENOVATE_CONFIG_FILE=default.json renovate-config-validator",
     "test:non-critical": "RENOVATE_CONFIG_FILE=non-critical.json renovate-config-validator",
     "test:third-party-major": "RENOVATE_CONFIG_FILE=third-party-major.json renovate-config-validator"
-  }
+  },
+  "packageManager": "pnpm@9.0.5"
 }