diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 5601d25..dfe5211 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -64,6 +64,7 @@ jobs:
     - uses: actions/checkout@v2
     - run: rustup update --no-self-update ${{ matrix.rust }} && rustup default ${{ matrix.rust }}
     - run: rustup target add ${{ matrix.other }}
+    - run: set RUSTFLAGS=-Dwarnings
 
     - name: windows build
       working-directory: ${{ matrix.crate }}