diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 44992bcd24..cb79e2e05c 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -198,6 +198,7 @@ jobs:
         run: cargo fetch --locked --target $TARGET
       - name: cargo fetch --locked difftests
         run: cargo fetch --locked --manifest-path=tests/difftests/tests/Cargo.toml --target $TARGET
+      - run: echo "RUST_LOG=debug" >> "$GITHUB_ENV"
       - name: test difftest
         run: cargo test -p "difftest*" --release --no-default-features --features "use-installed-tools"
       - name: difftests