diff --git a/.github/workflows/flutter-build.yml b/.github/workflows/flutter-build.yml
index d5789ad41..f621a983e 100644
--- a/.github/workflows/flutter-build.yml
+++ b/.github/workflows/flutter-build.yml
@@ -219,7 +219,7 @@ jobs:
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@v1
         with:
-          toolchain: ${{ env.RUST_VERSION }}-${{ matrix.job.target }}
+          toolchain: nightly-${{ matrix.job.target }} # must use nightly here, because of abi_thiscall feature required
           targets: ${{ matrix.job.target }}
           components: "rustfmt"