diff --git a/tests/test_config.py b/tests/test_config.py
index 69ebdc519..58dfe5d6a 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -72,4 +72,4 @@ def test_ssl_config(certfile_and_keyfile):
     config = Config(app=asgi_app, ssl_certfile=certfile.name, ssl_keyfile=keyfile.name)
     config.load()
 
-    assert bool(config.is_ssl) is True
+    assert config.is_ssl is True
diff --git a/uvicorn/config.py b/uvicorn/config.py
index 3830230eb..76abcee29 100644
--- a/uvicorn/config.py
+++ b/uvicorn/config.py
@@ -143,7 +143,7 @@ def __init__(
 
     @property
     def is_ssl(self) -> bool:
-        return self.ssl_keyfile or self.ssl_certfile
+        return bool(self.ssl_keyfile or self.ssl_certfile)
 
     def load(self):
         assert not self.loaded