diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0fd26ae..4c6386e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -31,6 +31,10 @@ jobs:
     continue-on-error: ${{ matrix.experimental }}
     steps:
       - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust }}
+          components: rustfmt
       - run: cargo test
       - run: cargo check --no-default-features --features flate2_zlib # Check without outline feature.
       - run: cargo check --no-default-features --features flate2_rust