diff --git a/testcases/filtertestcase.py b/testcases/filtertestcase.py
index 416423b3..6c29bdd6 100644
--- a/testcases/filtertestcase.py
+++ b/testcases/filtertestcase.py
@@ -223,11 +223,11 @@ class GetFailures(unittest.TestCase):
 class DNSUtilsTests(unittest.TestCase):
 
 	def testTextToIp(self):
+		# Bogus addresses which should have no DNS matches
 		bogus = [
-			'doh1.2.3.4.buga.xxxxx.yyy',
-			'1.2.3.4.buga.xxxxx.yyy',
+			'doh1.2.3.4.buga.xxxxx.yyy.invalid',
+			'1.2.3.4.buga.xxxxx.yyy.invalid',
 			]
-		"""Really bogus addresses which should have no matches"""
 		for s in bogus:
 			res = DNSUtils.textToIp(s)
 			self.assertEqual(res, [])