diff --git a/_unit-test/js-sdk-assets-test.sh b/_unit-test/js-sdk-assets-test.sh
index 5355a57076..30c2f07e46 100755
--- a/_unit-test/js-sdk-assets-test.sh
+++ b/_unit-test/js-sdk-assets-test.sh
@@ -11,16 +11,16 @@ source install/setup-js-sdk-assets.sh
 sdk_files=$(docker compose run --no-deps --rm -v "sentry-nginx-www:/var/www" nginx ls -lah /var/www/js-sdk/)
 sdk_tree=$(docker compose run --no-deps --rm -v "sentry-nginx-www:/var/www" nginx tree /var/www/js-sdk/ | tail -n 1)
 
-# `sdk_files` should contains 2 lines, `7.*` and `8.*`
+# `sdk_files` should contains 5 lines, '4.*', '5.*', '6.*', `7.*` and `8.*`
 echo $sdk_files
-total_directories=$(echo "$sdk_files" | grep -c '[78]\.[0-9]*\.[0-9]*$')
+total_directories=$(echo "$sdk_files" | grep -c '[45678]\.[0-9]*\.[0-9]*$')
 echo $total_directories
-test "2" == "$total_directories"
+test "5" == "$total_directories"
 echo "Pass"
 
-# `sdk_tree` should outputs "2 directories, 10 files"
+# `sdk_tree` should output "5 directories, 17 files"
 echo "$sdk_tree"
-test "2 directories, 10 files" == "$(echo "$sdk_tree")"
+test "5 directories, 17 files" == "$(echo "$sdk_tree")"
 echo "Pass"
 
 report_success
diff --git a/install/setup-js-sdk-assets.sh b/install/setup-js-sdk-assets.sh
index c8521ce8a5..f9261393f5 100644
--- a/install/setup-js-sdk-assets.sh
+++ b/install/setup-js-sdk-assets.sh
@@ -21,16 +21,32 @@ if [[ "${SETUP_JS_SDK_ASSETS:-}" == "1" ]]; then
   # We want to remove everything before the first '{'.
   loader_registry=$(echo "$loader_registry" | sed '0,/{/s/[^{]*//')
 
+  #  Sentry backend provides SDK versions from v4.x up to v8.x.
+  latest_js_v4=$(echo "$loader_registry" | $jq -r '.versions | reverse | map(select(.|any(.; startswith("4.")))) | .[0]')
+  latest_js_v5=$(echo "$loader_registry" | $jq -r '.versions | reverse | map(select(.|any(.; startswith("5.")))) | .[0]')
+  latest_js_v6=$(echo "$loader_registry" | $jq -r '.versions | reverse | map(select(.|any(.; startswith("6.")))) | .[0]')
   latest_js_v7=$(echo "$loader_registry" | $jq -r '.versions | reverse | map(select(.|any(.; startswith("7.")))) | .[0]')
   latest_js_v8=$(echo "$loader_registry" | $jq -r '.versions | reverse | map(select(.|any(.; startswith("8.")))) | .[0]')
 
-  echo "Found JS SDKs v${latest_js_v7} and v${latest_js_v8}, downloading from upstream.."
+  echo "Found JS SDKs: v${latest_js_v4}, v${latest_js_v5}, v${latest_js_v6}, v${latest_js_v7}, v${latest_js_v8}"
 
-  # Download those two using wget
-  for version in "${latest_js_v7}" "${latest_js_v8}"; do
+  versions=("$latest_js_v4" "$latest_js_v5" "$latest_js_v6" "$latest_js_v7" "$latest_js_v8")
+  variants=("bundle" "bundle.tracing" "bundle.tracing.replay" "bundle.replay" "bundle.tracing.replay.feedback" "bundle.feedback")
+
+  # Download those versions & variants using curl
+  for version in "${versions[@]}"; do
     $dcr --no-deps --rm -v "sentry-nginx-www:/var/www" nginx mkdir -p /var/www/js-sdk/${version}
-    for variant in "tracing" "tracing.replay" "replay" "tracing.replay.feedback" "feedback"; do
-      $dcr --no-deps --rm -v "sentry-nginx-www:/var/www" nginx wget -q -O /var/www/js-sdk/${version}/bundle.${variant}.min.js "https://browser.sentry-cdn.com/${version}/bundle.${variant}.min.js"
+    for variant in "${variants[@]}"; do
+      # We want to have a HEAD lookup. If the response status code is not 200, we will skip the variant.
+      # Taken from https://superuser.com/questions/272265/getting-curl-to-output-http-status-code#comment1025992_272273
+      status_code=$($dcr --no-deps --rm nginx curl --retry 5 -sLI "https://browser.sentry-cdn.com/${version}/${variant}.min.js" 2>/dev/null | head -n 1 | cut -d$' ' -f2)
+      if [[ "$status_code" != "200" ]]; then
+        echo "Skipping download of JS SDK v${version} for ${variant}.min.js, because the status code was ${status_code} (non 200)"
+        continue
+      fi
+
+      echo "Downloading JS SDK v${version} for ${variant}.min.js..."
+      $dcr --no-deps --rm -v "sentry-nginx-www:/var/www" nginx curl --retry 10 -sLo /var/www/js-sdk/${version}/${variant}.min.js "https://browser.sentry-cdn.com/${version}/${variant}.min.js"
     done
   done
 
diff --git a/unit-test.sh b/unit-test.sh
index 6cb81fa8d2..01a945e377 100755
--- a/unit-test.sh
+++ b/unit-test.sh
@@ -11,8 +11,9 @@ for test_file in _unit-test/*-test.sh; do
   fi
   echo "🙈 Running $test_file ..."
   $test_file
-  if [ $? != 0 ]; then
-    echo fail 👎
+  exit_code=$?
+  if [ $exit_code != 0 ]; then
+    echo fail 👎 with exit code $exit_code
     fail=1
   fi
 done