diff --git a/mempalace/config.py b/mempalace/config.py
index fd82be7..6e84de1 100644
--- a/mempalace/config.py
+++ b/mempalace/config.py
@@ -16,7 +16,7 @@ from pathlib import Path
 # in file paths, SQLite, or ChromaDB metadata.
 
 MAX_NAME_LENGTH = 128
-_SAFE_NAME_RE = re.compile(r"^[a-zA-Z0-9][a-zA-Z0-9_ .'-]{0,126}[a-zA-Z0-9]?$")
+_SAFE_NAME_RE = re.compile(r"^(?:[^\W_]|[^\W_][\w .'-]{0,126}[^\W_])$")
 
 
 def sanitize_name(value: str, field_name: str = "name") -> str:
diff --git a/tests/test_config.py b/tests/test_config.py
index a36b74d..761efe9 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -1,7 +1,9 @@
 import os
 import json
 import tempfile
-from mempalace.config import MempalaceConfig
+
+import pytest
+from mempalace.config import MempalaceConfig, sanitize_name
 
 
 def test_default_config():
@@ -30,3 +32,37 @@ def test_init():
     cfg = MempalaceConfig(config_dir=tmpdir)
     cfg.init()
     assert os.path.exists(os.path.join(tmpdir, "config.json"))
+
+
+# --- sanitize_name ---
+
+
+def test_sanitize_name_ascii():
+    assert sanitize_name("hello") == "hello"
+
+
+def test_sanitize_name_latvian():
+    assert sanitize_name("Jānis") == "Jānis"
+
+
+def test_sanitize_name_cjk():
+    assert sanitize_name("太郎") == "太郎"
+
+
+def test_sanitize_name_cyrillic():
+    assert sanitize_name("Алексей") == "Алексей"
+
+
+def test_sanitize_name_rejects_leading_underscore():
+    with pytest.raises(ValueError):
+        sanitize_name("_foo")
+
+
+def test_sanitize_name_rejects_path_traversal():
+    with pytest.raises(ValueError):
+        sanitize_name("../etc/passwd")
+
+
+def test_sanitize_name_rejects_empty():
+    with pytest.raises(ValueError):
+        sanitize_name("")