diff --git a/sendmail-8.14.3-ipv6-bad-helo.patch b/sendmail-8.14.3-ipv6-bad-helo.patch
deleted file mode 100644
index 1e8b493..0000000
--- a/sendmail-8.14.3-ipv6-bad-helo.patch
+++ /dev/null
@@ -1,8 +0,0 @@
---- sendmail-8.14.3/cf/feature/block_bad_helo.m4		2006-06-16 00:49:30.000000000 +0200
-+++ sendmail-8.14.3/cf/feature/block_bad_helo.m4.ipv6-bad-helo	2010-01-03 23:28:25.000000000 +0100
-@@ -16,3 +16,5 @@
- define(`_BLOCK_BAD_HELO_', `')dnl
- RELAY_DOMAIN(`127.0.0.1')dnl
- LOCAL_DOMAIN(`[127.0.0.1]')dnl
-+RELAY_DOMAIN(`IPv6:::1')dnl
-+LOCAL_DOMAIN(`[IPv6:::1]')dnl
diff --git a/sendmail-8.15.1-ipv6-bad-helo.patch b/sendmail-8.15.1-ipv6-bad-helo.patch
new file mode 100644
index 0000000..afd8ad0
--- /dev/null
+++ b/sendmail-8.15.1-ipv6-bad-helo.patch
@@ -0,0 +1,17 @@
+Patch by Robert Scheck <robert@fedoraproject.org> for sendmail >= 8.15.1 which ensures that the
+loopback IPv6 address is handled the same way like the IPv4 one. However since sendmail >= 8.15.1
+uncompressed IPv6 addresses are used by default thus the previously used IPv6:::1 gets changed to
+now IPv6:0:0:0:0:0:0:0:1 (if not compiled with -DIPV6_FULL=0 for the prior format). For further
+information see also:
+
+- https://bugzilla.redhat.com/show_bug.cgi?id=549217
+- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=618570
+ 
+--- sendmail-8.15.1/cf/feature/block_bad_helo.m4		2014-03-24 15:29:09.000000000 +0100
++++ sendmail-8.15.1/cf/feature/block_bad_helo.m4.ipv6-bad-helo	2015-03-20 01:22:42.000000000 +0100
+@@ -16,3 +16,5 @@
+ define(`_BLOCK_BAD_HELO_', `')dnl
+ RELAY_DOMAIN(`127.0.0.1')dnl
+ LOCAL_DOMAIN(`[127.0.0.1]')dnl
++RELAY_DOMAIN(`IPv6:0:0:0:0:0:0:0:1')dnl
++LOCAL_DOMAIN(`[IPv6:0:0:0:0:0:0:0:1]')dnl
diff --git a/sendmail.spec b/sendmail.spec
index f2862cf..f163fbb 100644
--- a/sendmail.spec
+++ b/sendmail.spec
@@ -21,7 +21,7 @@
 Summary: A widely used Mail Transport Agent (MTA)
 Name: sendmail
 Version: 8.15.1
-Release: 3%{?dist}
+Release: 4%{?dist}
 License: Sendmail
 Group: System Environment/Daemons
 URL: http://www.sendmail.org/
@@ -83,7 +83,7 @@ Patch17: sendmail-8.14.3-sharedmilter.patch
 # skip colon separator when parsing service name in ServiceSwitchFile
 Patch18: sendmail-8.15.1-switchfile.patch
 # handle IPv6:::1 in block_bad_helo.m4 like 127.0.0.1, #549217
-Patch21: sendmail-8.14.3-ipv6-bad-helo.patch
+Patch21: sendmail-8.15.1-ipv6-bad-helo.patch
 # silence warning about missing sasl2 config in /usr/lib*, now in /etc/sasl2
 Patch23: sendmail-8.14.8-sasl2-in-etc.patch
 # add QoS support, patch from Philip Prindeville <philipp@fedoraproject.org>
@@ -690,6 +690,9 @@ fi
 %endif
 
 %changelog
+* Fri Mar 20 2015 Robert Scheck <robert@fedoraproject.org> - 8.15.1-4
+- Use uncompressed (new) IPv6 address format in block_bad_helo.m4
+
 * Tue Mar 10 2015 Adam Jackson <ajax@redhat.com> 8.15.1-3
 - Drop sysvinit subpackage from F23+