diff --git a/tests/test_log.py b/tests/test_log.py
new file mode 100644
index 0000000..213f16f
--- /dev/null
+++ b/tests/test_log.py
@@ -0,0 +1,30 @@
+import unittest
+from pathlib import Path
+
+from glia._fs import get_cache_path, log
+
+
+class TestLog(unittest.TestCase):
+    def test_log_hash(self):
+        # We use the fact that Python salts hashes per session (see
+        # https://docs.python.org/3/using/cmdline.html#envvar-PYTHONHASHSEED) to get a
+        # a unique logfile hash per process, test this.
+        self.assertEqual(id("5"), id("5"))
+
+    def test_log(self):
+        log_path = Path(get_cache_path(f"{id('5')}.txt"))
+        log_path.unlink(missing_ok=True)
+        log("hello world")
+        self.assertTrue(log_path.exists(), "Logs not created")
+        self.assertIn("hello world", log_path.read_text(), "Log not logged")
+
+    def test_exc(self):
+        log_path = Path(get_cache_path(f"{id('5')}.txt"))
+        log_path.unlink(missing_ok=True)
+        try:
+            raise RuntimeError()
+        except RuntimeError as e:
+            log("hello world", exc=e)
+        self.assertTrue(log_path.exists(), "Logs not created")
+        # Check log level elevation to ERROR
+        self.assertIn("ERROR] hello world", log_path.read_text(), "Exc not logged")