diff --git a/radvd-endianess.patch b/radvd-endianess.patch
new file mode 100644
index 0000000..9893eea
--- /dev/null
+++ b/radvd-endianess.patch
@@ -0,0 +1,82 @@
+From 05f06df832f1a9da671d431c19191c47ec48e722 Mon Sep 17 00:00:00 2001
+From: Sergei Trofimovich <slyfox@gentoo.org>
+Date: Fri, 17 Nov 2017 23:40:20 +0000
+Subject: [PATCH] nd_opt_6co: use uint8_t as a bitfield to be
+ endianness-agnostic
+
+Bug: https://github.com/reubenhwk/radvd/issues/77
+Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
+---
+ radvd.h     | 4 +---
+ send.c      | 4 ++--
+ test/send.c | 3 +--
+ 3 files changed, 4 insertions(+), 7 deletions(-)
+
+diff --git a/radvd.h b/radvd.h
+index 89a5b9e..f520f24 100644
+--- a/radvd.h
++++ b/radvd.h
+@@ -259,9 +259,7 @@ struct nd_opt_6co {
+ 	uint8_t nd_opt_6co_type;
+ 	uint8_t nd_opt_6co_len;
+ 	uint8_t nd_opt_6co_context_len;
+-	uint8_t nd_opt_6co_res : 3;
+-	uint8_t nd_opt_6co_c : 1;
+-	uint8_t nd_opt_6co_cid : 4;
++	uint8_t nd_opt_6co_res_c_cid; /* [ res=3-bits | c=1-bit | cid=4-bits ] */
+ 	uint16_t nd_opt_6co_reserved;
+ 	uint16_t nd_opt_6co_valid_lifetime;
+ 	struct in6_addr nd_opt_6co_con_prefix;
+diff --git a/send.c b/send.c
+index 8bc16a8..d44f85c 100644
+--- a/send.c
++++ b/send.c
+@@ -619,8 +619,8 @@ static void add_ra_option_lowpanco(struct safe_buffer *sb, struct AdvLowpanCo co
+ 	co.nd_opt_6co_type = ND_OPT_6CO;
+ 	co.nd_opt_6co_len = 3;
+ 	co.nd_opt_6co_context_len = lowpanco->ContextLength;
+-	co.nd_opt_6co_c = lowpanco->ContextCompressionFlag;
+-	co.nd_opt_6co_cid = lowpanco->AdvContextID;
++	co.nd_opt_6co_res_c_cid = ((lowpanco->ContextCompressionFlag ? 1 : 0) << 4)
++				| (lowpanco->AdvContextID & 0x0F);
+ 	co.nd_opt_6co_valid_lifetime = lowpanco->AdvLifeTime;
+ 	co.nd_opt_6co_con_prefix = lowpanco->AdvContextPrefix;
+ 
+diff --git a/test/send.c b/test/send.c
+index 92fe45b..4124986 100644
+--- a/test/send.c
++++ b/test/send.c
+@@ -309,10 +309,9 @@ START_TEST(test_add_ra_option_lowpanco)
+ 	ck_assert_msg(0, "\n%s", &buf);
+ #else
+ 	unsigned char expected[] = {
+-	    0x22, 0x03, 0x32, 0x48, 0x00, 0x00, 0xe8, 0x03, 0x00, 0x00, 0x00, 0x00,
++	    0x22, 0x03, 0x32, 0x14, 0x00, 0x00, 0xe8, 0x03, 0x00, 0x00, 0x00, 0x00,
+ 	    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 	};
+-
+ 	ck_assert_int_eq(sb.used, sizeof(expected));
+ 	ck_assert_int_eq(0, memcmp(expected, sb.buffer, sizeof(expected)));
+ #endif
+diff --git a/test/send.c b/test/send.c
+index 4124986..b194449 100644
+--- a/test/send.c
++++ b/test/send.c
+@@ -309,7 +309,7 @@ START_TEST(test_add_ra_option_lowpanco)
+ 	ck_assert_msg(0, "\n%s", &buf);
+ #else
+ 	unsigned char expected[] = {
+-	    0x22, 0x03, 0x32, 0x14, 0x00, 0x00, 0xe8, 0x03, 0x00, 0x00, 0x00, 0x00,
++	    0x22, 0x03, 0x32, 0x14, 0x00, 0x00, 0x03, 0xe8, 0x00, 0x00, 0x00, 0x00,
+ 	    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 	};
+ 	ck_assert_int_eq(sb.used, sizeof(expected));
+@@ -333,7 +333,7 @@ START_TEST(test_add_ra_option_abro)
+ 	ck_assert_msg(0, "\n%s", &buf);
+ #else
+ 	unsigned char expected[] = {
+-	    0x23, 0x03, 0x0a, 0x00, 0x02, 0x00, 0x02, 0x00, 0xfe, 0x80, 0x00, 0x00,
++	    0x23, 0x03, 0x00, 0x0a, 0x00, 0x02, 0x00, 0x02, 0xfe, 0x80, 0x00, 0x00,
+ 	    0x00, 0x00, 0x00, 0x00, 0xa2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
+ 	};
+ 
diff --git a/radvd.spec b/radvd.spec
index 32aaca3..ef2ceb6 100644
--- a/radvd.spec
+++ b/radvd.spec
@@ -11,6 +11,7 @@ Source1: radvd-tmpfs.conf
 Source2: radvd.service
 ## https://github.com/reubenhwk/radvd/commit/6e45acbf3d64b9bd945adcb3de622fd7d059ceb9.patch
 Patch0: radvd-werror.patch
+Patch1: radvd-endianess.patch
 
 BuildRequires: gcc
 BuildRequires: bison
@@ -36,6 +37,7 @@ services.
 %prep
 %setup -q
 %patch0 -p1 -b .werror
+%patch1 -p1 -b .endianess
 
 for F in CHANGES; do
     iconv -f iso-8859-1 -t utf-8 < "$F" > "${F}.new"
@@ -44,9 +46,10 @@ for F in CHANGES; do
 done
 
 %build
-export CFLAGS="$RPM_OPT_FLAGS -fPIE -Werror=all" 
+export CFLAGS="$RPM_OPT_FLAGS -fPIE " 
 export LDFLAGS='-pie -Wl,-z,relro,-z,now,-z,noexecstack,-z,nodlopen'
 %configure \
+    --with-check \
     --disable-silent-rules \
     --with-pidfile=/run/radvd/radvd.pid
 make %{?_smp_mflags} 
@@ -67,7 +70,7 @@ install -m 644 %{SOURCE2} %{buildroot}%{_unitdir}
 
 %check
 # The tests don't work, see https://github.com/reubenhwk/radvd/issues/30
-#make check
+make check
 
 %postun
 %systemd_postun_with_restart radvd.service