diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 542db75..a9437bb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,8 @@ jobs:
   check:
     name: cargo check
     runs-on: ubuntu-latest
+    env:
+      RUSTFLAGS: -D warnings
     steps:
       - uses: actions/checkout@v4
       - uses: actions-rust-lang/setup-rust-toolchain@v1