diff --git a/tools/hako_check/run_tests.sh b/tools/hako_check/run_tests.sh
index 4c0194c9..d05cea0c 100644
--- a/tools/hako_check/run_tests.sh
+++ b/tools/hako_check/run_tests.sh
@@ -94,10 +94,26 @@ run_case() {
   rm -f "$tmp_out" "$tmp_norm" "$tmp_json"
 }
 
-for d in "$TARGET_DIR"/*; do
-  [ -d "$d" ] || continue
-  run_case "$d"
-done
+# Handle arguments: if provided, test only specified dirs; otherwise test all
+if [ $# -gt 0 ]; then
+  # Test only specified directories
+  for arg in "$@"; do
+    # Convert relative path to absolute
+    if [[ "$arg" == /* ]]; then
+      d="$arg"
+    else
+      d="$ROOT/$arg"
+    fi
+    [ -d "$d" ] || { echo "[TEST] not a directory: $d" >&2; continue; }
+    run_case "$d"
+  done
+else
+  # Test all directories
+  for d in "$TARGET_DIR"/*; do
+    [ -d "$d" ] || continue
+    run_case "$d"
+  done
+fi
 
 if [ $fail -ne 0 ]; then
   echo "[TEST/SUMMARY] failures=$fail" >&2