diff --git a/.github/workflows/workflow.yml b/.github/workflows/workflow.yml
index 60b6009..6ab31f1 100644
--- a/.github/workflows/workflow.yml
+++ b/.github/workflows/workflow.yml
@@ -43,3 +43,17 @@ jobs:
     - name: Run flutter --version
       shell: bash
       run: flutter --version
+  test_master:
+    runs-on: windows-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+    - uses: ./
+      with:
+        channel: master
+    - name: Run dart --version
+      shell: bash
+      run: dart --version
+    - name: Run flutter --version
+      shell: bash
+      run: flutter --version
diff --git a/setup.sh b/setup.sh
index aef15b2..c585f0a 100755
--- a/setup.sh
+++ b/setup.sh
@@ -59,23 +59,21 @@ download_archive() {
 
 CHANNEL="$1"
 VERSION="$2"
-VERSION_MANIFEST=$(get_version_manifest $CHANNEL $VERSION)
 
-if [[ $VERSION_MANIFEST == null ]]; then
-  echo "Unable to determine Flutter version for $CHANNEL $VERSION"
-  exit 1
+if [[ $CHANNEL == master ]]; then
+  git clone -b master https://github.com/flutter/flutter.git "$RUNNER_TOOL_CACHE/flutter"
+else
+  VERSION_MANIFEST=$(get_version_manifest $CHANNEL $VERSION)
+
+  if [[ $VERSION_MANIFEST == null ]]; then
+    echo "Unable to determine Flutter version for $CHANNEL $VERSION"
+    exit 1
+  fi
+
+  ARCHIVE_PATH=$(echo $VERSION_MANIFEST | jq -r '.archive')
+  download_archive "$ARCHIVE_PATH" "$RUNNER_TOOL_CACHE"
 fi
 
-echo $OS_NAME
-echo $MANIFEST_URL
-echo $CHANNEL
-echo $VERSION
-echo $VERSION_MANIFEST
-
-ARCHIVE_PATH=$(echo $VERSION_MANIFEST | jq -r '.archive')
-
-download_archive "$ARCHIVE_PATH" "$RUNNER_TOOL_CACHE"
-
 if [[ $OS_NAME == windows ]]; then
   FLUTTER_ROOT="${RUNNER_TOOL_CACHE}\\flutter"
   PUBCACHE="${USERPROFILE}\\.pub-cache"