diff --git a/falcon/util/sync.py b/falcon/util/sync.py
index 8065f0c51..38b2bd5d1 100644
--- a/falcon/util/sync.py
+++ b/falcon/util/sync.py
@@ -236,11 +236,12 @@ def async_to_sync(
     Keyword Args:
         **kwargs: Additional args are passed through to the coroutine function.
     """
+    global _runner
     # NOTE(vytas): Sometimes our runner's loop can get picked and consumed by
     #   other utilities and test methods. If that happens, recreate the runner.
-    global _runner
     if _runner.get_loop().is_closed():
-        _runner = _runner_cls()
+        # NOTE(vytas): This condition is never hit on _DummyRunner.
+        _runner = _runner_cls()  # pragma: nocover
     return _runner.run(coroutine(*args, **kwargs))
 
 
diff --git a/pyproject.toml b/pyproject.toml
index ad445ce55..5ed0c5fab 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -97,7 +97,6 @@ filterwarnings = [
     "ignore:.cgi. is deprecated and slated for removal:DeprecationWarning",
     "ignore:path is deprecated\\. Use files\\(\\) instead:DeprecationWarning",
     "ignore:This process \\(.+\\) is multi-threaded",
-    "ignore:There is no current event loop",
 ]
 testpaths = [
     "tests"