diff --git a/scripts/setup_runner_mac.sh b/scripts/setup_runner_mac.sh
index d028f36..53ddbeb 100755
--- a/scripts/setup_runner_mac.sh
+++ b/scripts/setup_runner_mac.sh
@@ -56,33 +56,25 @@ mkdir -p "$(dirname "$CONFIG_PATH")"
 "$INSTALL_DIR/act_runner" generate-config > "$CONFIG_PATH"
 
 # Patch labels, cache host/port, and capacity
-python3 - "$CONFIG_PATH" "$HOST_IP" "$CACHE_PORT" <<'PYEOF'
-import sys, re
+awk -v host="$HOST_IP" -v port="$CACHE_PORT" '
+  /^runner:/          { in_runner=1; in_cache=0 }
+  /^cache:/           { in_cache=1; in_runner=0 }
+  /^[a-z]/ && !/^runner:/ && !/^cache:/ { in_runner=0; in_cache=0 }
 
-path, host_ip, port = sys.argv[1], sys.argv[2], sys.argv[3]
-with open(path) as f:
-    content = f.read()
+  in_runner && /capacity:/  { $0 = "  capacity: 1" }
+  in_runner && /labels:/    { print; skip_labels=1; next }
+  skip_labels && /^  - /    { next }
+  skip_labels && !/^  - /   { skip_labels=0
+                               print "  - \"macos-latest:host\""
+                               print "  - \"macos-14:host\"" }
 
-# labels
-content = re.sub(
-    r'(labels:\s*\n)(\s+-.*\n)+',
-    'labels:\n  - "macos-latest:host"\n  - "macos-14:host"\n',
-    content
-)
-# cache enabled
-content = re.sub(r'(cache:.*?\n\s+enabled:\s*)false', r'\g<1>true', content, flags=re.DOTALL)
-# cache host
-content = re.sub(r'(  host:\s*)""', f'  host: "{host_ip}"', content)
-# cache port
-content = re.sub(r'(  port:\s*)\d+', f'  port: {port}', content)
-# capacity
-content = re.sub(r'(  capacity:\s*)\d+', r'  capacity: 1', content)
+  in_cache && /enabled:/    { $0 = "  enabled: true" }
+  in_cache && /host:/       { $0 = "  host: \"" host "\"" }
+  in_cache && /port:/       { $0 = "  port: " port; in_cache=0 }
 
-with open(path, 'w') as f:
-    f.write(content)
-
-print(f"Config patched: labels=macos-latest:host, cache={host_ip}:{port}")
-PYEOF
+  { print }
+' "$CONFIG_PATH" > "${CONFIG_PATH}.tmp" && mv "${CONFIG_PATH}.tmp" "$CONFIG_PATH"
+echo "Config patched: labels=macos-latest:host, cache=$HOST_IP:$CACHE_PORT"
 
 # ── register runner ───────────────────────────────────────────────────────────
 echo "Registering runner '$RUNNER_NAME'..."