diff --git a/scripts/update-appup.sh b/scripts/update-appup.sh
index e1ef0c3c0..db0759695 100755
--- a/scripts/update-appup.sh
+++ b/scripts/update-appup.sh
@@ -41,18 +41,20 @@ shift 1
 ESCRIPT_ARGS="$*"
 
 SYSTEM="${SYSTEM:-$(./scripts/get-distro.sh)}"
-ARCH="${ARCH:-$(uname -m)}"
-case "$ARCH" in
-    x86_64)
-        ARCH='amd64'
-        ;;
-    aarch64)
-        ARCH='arm64'
-        ;;
-    arm*)
-        ARCH=arm
-        ;;
-esac
+if [ -z "${ARCH:-}" ]; then
+    UNAME="$(uname -m)"
+    case "$UNAME" in
+        x86_64)
+            ARCH='amd64'
+            ;;
+        aarch64)
+            ARCH='arm64'
+            ;;
+        arm*)
+            ARCH='arm'
+            ;;
+    esac
+fi
 
 PACKAGE_NAME="${PROFILE}-${SYSTEM}-${PREV_VERSION}-${ARCH}.zip"
 DOWNLOAD_URL="https://www.emqx.com/downloads/${DIR}/v${PREV_VERSION}/${PACKAGE_NAME}"
diff --git a/scripts/update_appup.escript b/scripts/update_appup.escript
index 5bc709267..b12012719 100755
--- a/scripts/update_appup.escript
+++ b/scripts/update_appup.escript
@@ -171,9 +171,11 @@ download_prev_release(Tag, #{binary_rel_url := {ok, URL0}, clone_url := Repo}) -
     BaseDir = "/tmp/emqx-baseline-bin/",
     Dir = filename:basename(Repo, ".git") ++ [$-|Tag],
     Filename = filename:join(BaseDir, Dir),
-    Script = "echo \"Download: ${OUTFILE}\" &&
-              mkdir -p ${OUTFILE} &&
-              curl -f -L -o ${OUTFILE}.zip ${URL} &&
+    Script = "mkdir -p ${OUTFILE} &&
+              if [ ! -f \"${OUTFILE}.zip\" ]; then \
+                echo \"Download: ${OUTFILE}\" && \
+                curl -f -L -o \"${OUTFILE}.zip\" \"${URL}\"; \
+              fi &&
               unzip -q -n -d ${OUTFILE} ${OUTFILE}.zip",
     Env = [{"TAG", Tag}, {"OUTFILE", Filename}, {"URL", URL}],
     bash(Script, Env),