diff --git a/tests/test_utils.py b/tests/test_utils.py
index c5bdd74..5ce0d5a 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -16,6 +16,9 @@
         ("https//example..com", False),
         ("http://www.asdf.com", True),
         ("http://A1-B2.C3D4.E5F6.COM", True),
+        ("-", False),
+        ("//www.host.com", True),
+        ("www.host.com", False),
     ],
 )
 def test_is_valid_uri(url, expected):