diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 48aa1f3..0b33c99 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -11,18 +11,13 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: true
 
-# Fail every cargo invocation on warnings from workspace-local packages
-# (cargo's build.warnings, stable since 1.97). CI-only: local builds
-# still just warn.
-env:
-  CARGO_BUILD_WARNINGS: deny
-
 jobs:
   lean-test:
     name: Lean Tests
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
+      - uses: actions-rust-lang/setup-rust-toolchain@v2
       - uses: leanprover/lean-action@v1
         with:
           build-args: "--wfail"
@@ -33,12 +28,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v7
-      - uses: actions-rust-lang/setup-rust-toolchain@v1
-        with:
-          # Warnings are handled by CARGO_BUILD_WARNINGS above, which applies
-          # to local packages only. The action defaults to `-D warnings`,
-          # which also denies warnings from dependencies.
-          rustflags: ""
+      - uses: actions-rust-lang/setup-rust-toolchain@v2
       # Only restore the cache, since the `test` job will save the test binary to the cache first
       - uses: actions/cache/restore@v6
         with: