diff --git a/flutter.sh b/flutter.sh
index bf755b6..7634bc3 100755
--- a/flutter.sh
+++ b/flutter.sh
@@ -2,7 +2,7 @@
 # requires: curl, unzip, gsutil, jq
 
 DEST_DIR="${TUNASYNC_WORKING_DIR}"
-STABLE_VERSION_ENGINE=true
+SYNC_FLUTTER_ENGINES=latest_tags
 
 gsutil rsync -d -C -r -x '(1\..+/|\d{5}/|.+/api-docs)' gs://dart-archive/channels/stable/release \
     "${DEST_DIR}/dart-archive/channels/stable/release"
@@ -10,27 +10,35 @@ gsutil rsync -d -C -r -x '(dev|beta)' gs://flutter_infra/releases \
     "${DEST_DIR}/flutter_infra/releases"
 
 
-if [[ "$STABLE_VERSION_ENGINE" == "true" ]];then
-    for i in ${DEST_DIR}/flutter_infra/releases/stable/macos/*.zip; do
-        engine_version=$(unzip -p "$i" flutter/bin/internal/engine.version)
-        echo "======== name ${i##*/}, engine version ($engine_version) ========"
-        path=flutter_infra/flutter/$engine_version
-        mkdir -p "${DEST_DIR}/$path" 2>/dev/null || true
-        gsutil -m rsync -d -C -r "gs://$path" "${DEST_DIR}/$path"
-    done
-else
+function sync_engine() {
+    [[ -z "$1" ]] && exit 1
+    path="flutter_infra/flutter/$1"
+    mkdir -p "${DEST_DIR}/$path" 2>/dev/null || true
+    gsutil -m rsync -d -C -r "gs://$path" "${DEST_DIR}/$path"
+}
+
+if [[ "$SYNC_FLUTTER_ENGINES" == "recent_tags" ]]; then
     curl -H "Authorization: token $GITHUB_TOKEN" "https://api.github.com/repos/flutter/flutter/tags" | \
         jq -r '.[]| [.name]| @tsv' | \
         while IFS=$'\t' read -r name; do
             engine_version=$(curl "https://raw.githubusercontent.com/flutter/flutter/$name/bin/internal/engine.version")
             echo "======== tag $name, engine version ($engine_version) ========"
-            path=flutter_infra/flutter/$engine_version
-            mkdir -p "${DEST_DIR}/$path" 2>/dev/null || true
-            gsutil -m rsync -d -C -r "gs://$path" "${DEST_DIR}/$path"
+            sync_engine "$engine_version"
         done
-fi
+elif [[ "$SYNC_FLUTTER_ENGINES" == "latest_tags" ]]; then
+    for branch in stable beta dev; do
+        engine_version=$(curl "https://raw.githubusercontent.com/flutter/flutter/$branch/bin/internal/engine.version")
+        echo "======== branch ${branch}, engine version ($engine_version) ========"
+        sync_engine "$engine_version"
 
-exit 0
+        for i in ${DEST_DIR}/flutter_infra/releases/${branch}/macos/*.zip; do
+            [[ -f "$i" ]] || continue
+            engine_version=$(unzip -p "$i" flutter/bin/internal/engine.version)
+            echo "======== installer name ${i##*/}, engine version ($engine_version) ========"
+            sync_engine "$engine_version"
+        done
+    done
+fi
 
 for path in "flutter_infra/ios-usb-dependencies" \
             "flutter_infra/flutter/fonts" \