diff --git a/include/sentry.h b/include/sentry.h
index a6ceadc41..16b7e03fc 100644
--- a/include/sentry.h
+++ b/include/sentry.h
@@ -1068,6 +1068,11 @@ typedef void (*sentry_logger_function_t)(
  * Sets the sentry-native logger function.
  *
  * Used for logging debug events when the `debug` option is set to true.
+ *
+ * Note: Multiple threads may invoke your `func`. If you plan to mutate any data
+ * inside the `userdata` argument after initialization, you must ensure proper
+ * synchronization inside the logger function.
+ *
  */
 SENTRY_API void sentry_options_set_logger(
     sentry_options_t *opts, sentry_logger_function_t func, void *userdata);
diff --git a/tests/test_unit.py b/tests/test_unit.py
index f75a719d7..3633efec9 100644
--- a/tests/test_unit.py
+++ b/tests/test_unit.py
@@ -14,6 +14,9 @@ def test_unit(cmake, unittest):
 
 @pytest.mark.skipif(not has_http, reason="tests need http transport")
 def test_unit_transport(cmake, unittest):
+    if unittest in ["custom_logger"]:
+        pytest.skip("excluded from transport test-suite")
+
     cwd = cmake(["sentry_test_unit"], {"SENTRY_BACKEND": "none"})
     env = dict(os.environ)
     run(cwd, "sentry_test_unit", ["--no-summary", unittest], check=True, env=env)