diff --git a/.github/workflows/Swift.yml b/.github/workflows/Swift.yml
index d308890a..a5209331 100644
--- a/.github/workflows/Swift.yml
+++ b/.github/workflows/Swift.yml
@@ -38,4 +38,4 @@ jobs:
       - run: wasmtime -V
       - run: swift sdk install https://github.com/swiftwasm/swift/releases/download/swift-wasm-DEVELOPMENT-SNAPSHOT-2024-07-16-a/swift-wasm-DEVELOPMENT-SNAPSHOT-2024-07-16-a-wasm32-unknown-wasip1-threads.artifactbundle.zip
       - run: swift build -c release --build-tests --swift-sdk wasm32-unknown-wasip1-threads -Xlinker -z -Xlinker stack-size=$STACK_SIZE
-      - run: wasmtime --dir / --wasm max-wasm-stack=$STACK_SIZE .build/release/swift-formatPackageTests.wasm
+      - run: wasmtime --dir / --wasm max-wasm-stack=$STACK_SIZE --wasi threads .build/release/swift-formatPackageTests.wasm