diff --git a/0001-struct-sockaddr-is-not-large-enough-to-store-a-gener.patch b/0001-struct-sockaddr-is-not-large-enough-to-store-a-gener.patch
new file mode 100644
index 0000000..1a74ccb
--- /dev/null
+++ b/0001-struct-sockaddr-is-not-large-enough-to-store-a-gener.patch
@@ -0,0 +1,58 @@
+From 49c5ff9ad0316960f11b180715b3a6906d42be83 Mon Sep 17 00:00:00 2001
+From: Michael Scherer <misc@zarb.org>
+Date: Sun, 21 Jul 2013 21:59:28 +0100
+Subject: [PATCH] 'struct sockaddr' is not large enough to store a general
+ sockaddr.
+
+In particular, if IPv6 is used, then sizeof sockaddr_in6 > sizeof sockaddr,
+resulting in a segfault:
+
+https://bugzilla.redhat.com/show_bug.cgi?id=986601
+
+RWMJ:
+ - Minor formatting
+ - Free tls->addr on normal exit path
+---
+ src/tls.c | 12 +++++++++---
+ 1 file changed, 9 insertions(+), 3 deletions(-)
+
+diff --git a/src/tls.c b/src/tls.c
+index 08e8638..390b03e 100644
+--- a/src/tls.c
++++ b/src/tls.c
+@@ -54,7 +54,7 @@
+ struct tls {
+   const char *name;             /* Can be NULL. */
+   size_t instance_num;          /* Can be 0. */
+-  struct sockaddr addr;
++  struct sockaddr *addr;
+   socklen_t addrlen;
+ };
+ 
+@@ -65,6 +65,7 @@ free_tls (void *tlsv)
+ {
+   struct tls *tls = tlsv;
+ 
++  free (tls->addr);
+   free (tls);
+ }
+ 
+@@ -118,8 +119,13 @@ tls_set_sockaddr (struct sockaddr *addr, socklen_t addrlen)
+   struct tls *tls = pthread_getspecific (tls_key);
+ 
+   if (tls) {
+-    tls->addrlen = addrlen;
+-    memcpy (&tls->addr, addr, addrlen);
++    free(tls->addr);
++    tls->addr = calloc (1, addrlen);
++    if (tls->addr == NULL) {
++      perror ("calloc");
++      exit (EXIT_FAILURE);
++    }
++    memcpy(tls->addr, addr, addrlen);
+   }
+ }
+ 
+-- 
+1.8.3.1
+
diff --git a/nbdkit.spec b/nbdkit.spec
index 86bd254..a79933c 100644
--- a/nbdkit.spec
+++ b/nbdkit.spec
@@ -2,13 +2,17 @@
 
 Name:           nbdkit
 Version:        1.1.2
-Release:        2%{?dist}
+Release:        3%{?dist}
 Summary:        NBD server
 
 License:        BSD
 URL:            https://github.com/libguestfs/nbdkit
 Source0:        http://libguestfs.org/download/nbdkit/%{name}-%{version}.tar.gz
 
+# Fix segfault when IPv6 client is used (RHBZ#986601).
+# Patch is upstream.
+Patch1:         0001-struct-sockaddr-is-not-large-enough-to-store-a-gener.patch
+
 BuildRequires:  /usr/bin/pod2man
 BuildRequires:  libguestfs-devel
 BuildRequires:  libvirt-devel
@@ -121,6 +125,7 @@ plugins for %{name}.
 
 %prep
 %setup -q
+%patch1 -p1
 
 
 %build
@@ -199,6 +204,9 @@ make check
 
 
 %changelog
+* Sun Jul 21 2013 Richard W.M. Jones <rjones@redhat.com> - 1.1.2-3
+- Fix segfault when IPv6 client is used (RHBZ#986601).
+
 * Tue Jul 16 2013 Richard W.M. Jones <rjones@redhat.com> - 1.1.2-2
 - New development version 1.1.2.
 - Disable the tests on Fedora <= 18.