diff --git a/fail2ban/tests/filtertestcase.py b/fail2ban/tests/filtertestcase.py
index 8027846e..8617e233 100644
--- a/fail2ban/tests/filtertestcase.py
+++ b/fail2ban/tests/filtertestcase.py
@@ -2200,11 +2200,13 @@ class DNSUtilsNetworkTests(unittest.TestCase):
 
 	def testIpToName(self):
 		#unittest.F2B.SkipIfNoNetwork()
-		res = DNSUtils.ipToName('8.8.4.4')
-		self.assertTrue(res.endswith(('.google', '.google.com')))
+		self.assertEqual(DNSUtils.ipToName('87.142.124.10'), 'test-host')
+		self.assertEqual(DNSUtils.ipToName('2001:db8::ffff'), 'test-other')
+		res = DNSUtils.ipToName('199.9.14.201')
+		self.assertTrue(res.endswith(('.isi.edu', '.b.root-servers.org')))
 		# same as above, but with IPAddr:
-		res = DNSUtils.ipToName(IPAddr('8.8.4.4'))
-		self.assertTrue(res.endswith(('.google', '.google.com')))
+		res = DNSUtils.ipToName(IPAddr('199.9.14.201'))
+		self.assertTrue(res.endswith(('.isi.edu', '.b.root-servers.org')))
 		# invalid ip (TEST-NET-1 according to RFC 5737)
 		res = DNSUtils.ipToName('192.0.2.0')
 		self.assertEqual(res, None)
diff --git a/fail2ban/tests/utils.py b/fail2ban/tests/utils.py
index bd4c7e02..ef908ddb 100644
--- a/fail2ban/tests/utils.py
+++ b/fail2ban/tests/utils.py
@@ -311,7 +311,8 @@ def initTests(opts):
 		# precache all ip to dns used in test cases:
 		c.set('192.0.2.888', None)
 		c.set('8.8.4.4', 'dns.google')
-		c.set('8.8.4.4', 'dns.google')
+		c.set('8.8.8.8', 'dns.google')
+		c.set('199.9.14.201', 'b-2017.b.root-servers.org')
 		# precache all dns to ip's used in test cases:
 		c = DNSUtils.CACHE_nameToIp
 		c.clear = lambda: logSys.warning('clear CACHE_nameToIp is disabled in test suite')