diff --git a/fail2ban/tests/utils.py b/fail2ban/tests/utils.py
index 7fba73c9..5f144547 100644
--- a/fail2ban/tests/utils.py
+++ b/fail2ban/tests/utils.py
@@ -269,7 +269,9 @@ def initTests(opts):
 
 	# precache all invalid ip's (TEST-NET-1, ..., TEST-NET-3 according to RFC 5737):
 	c = DNSUtils.CACHE_ipToName
-	for i in xrange(255):
+	# increase max count and max time (too many entries, long time testing):
+	c.setOptions(maxCount=10000, maxTime=5*60)
+	for i in xrange(256):
 		c.set('192.0.2.%s' % i, None)
 		c.set('198.51.100.%s' % i, None)
 		c.set('203.0.113.%s' % i, None)