diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index a04d6730f..0814f9d60 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,7 +8,10 @@ jobs:
     name: Build and Test
     strategy:
       matrix:
-        os: [macOS-10.15, Ubuntu-18.04]
+        os: [macos-10.15, macos-11, ubuntu-18.04, ubuntu-20.04]
+        toolchain:
+          - wasm-5.3.1-RELEASE
+          - wasm-5.4.0-RELEASE
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout
@@ -21,5 +24,6 @@ jobs:
           export SWIFTENV_ROOT="$HOME/.swiftenv"
           export PATH="$SWIFTENV_ROOT/bin:$PATH"
           eval "$(swiftenv init -)"
-          make bootstrap
+          SWIFT_VERSION=${{ matrix.toolchain }} make bootstrap
+          echo ${{ matrix.toolchain }} > .swift-version
           make test
diff --git a/scripts/install-toolchain.sh b/scripts/install-toolchain.sh
index 068d4ff14..ef085aaaf 100755
--- a/scripts/install-toolchain.sh
+++ b/scripts/install-toolchain.sh
@@ -3,16 +3,17 @@ set -eu
 
 scripts_dir="$(cd "$(dirname $0)" && pwd)"
 
-swift_version="$(cat $scripts_dir/../.swift-version)"
-swift_tag="swift-$swift_version"
+default_swift_version="$(cat $scripts_dir/../.swift-version)"
+SWIFT_VERSION="${SWIFT_VERSION:-$default_swift_version}"
+swift_tag="swift-$SWIFT_VERSION"
 
 if [ -z "$(which swiftenv)" ]; then
   echo "swiftenv not installed, please install it before this script."
   exit 1
 fi
 
-if [ ! -z "$(swiftenv versions | grep $swift_version)" ]; then
-  echo "$swift_version is already installed."
+if [ ! -z "$(swiftenv versions | grep $SWIFT_VERSION)" ]; then
+  echo "$SWIFT_VERSION is already installed."
   exit 0
 fi