diff --git a/libgcrypt-1.6.3-aliasing.patch b/libgcrypt-1.6.3-aliasing.patch
new file mode 100644
index 0000000..9282944
--- /dev/null
+++ b/libgcrypt-1.6.3-aliasing.patch
@@ -0,0 +1,177 @@
+diff -up libgcrypt-1.6.3/cipher/bufhelp.h.aliasing libgcrypt-1.6.3/cipher/bufhelp.h
+--- libgcrypt-1.6.3/cipher/bufhelp.h.aliasing	2015-02-27 10:54:03.000000000 +0100
++++ libgcrypt-1.6.3/cipher/bufhelp.h	2015-03-13 15:03:43.301749751 +0100
+@@ -80,7 +80,7 @@ do_bytes:
+   for (; len; len--)
+     *dst++ = *src++;
+ #endif /*__GNUC__ >= 4 && (__x86_64__ || __i386__)*/
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ 
+ /* Optimized function for buffer xoring */
+@@ -117,7 +117,7 @@ do_bytes:
+   /* Handle tail.  */
+   for (; len; len--)
+     *dst++ = *src1++ ^ *src2++;
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ 
+ /* Optimized function for buffer xoring with two destination buffers.  Used
+@@ -155,7 +155,7 @@ do_bytes:
+   /* Handle tail.  */
+   for (; len; len--)
+     *dst1++ = (*dst2++ ^= *src++);
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ 
+ /* Optimized function for combined buffer xoring and copying.  Used by mainly
+@@ -208,7 +208,7 @@ do_bytes:
+       *dst_xor++ = *srcdst_cpy ^ *src_xor++;
+       *srcdst_cpy++ = temp;
+     }
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ 
+ /* Optimized function for combined buffer xoring and copying.  Used by mainly
+@@ -234,7 +234,7 @@ buf_eq_const(const void *_a, const void
+     diff -= !!(a[i] - b[i]);
+ 
+   return !diff;
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ 
+ #ifndef BUFHELP_FAST_UNALIGNED_ACCESS
+@@ -246,14 +246,14 @@ static inline u32 buf_get_be32(const voi
+   const byte *in = _buf;
+   return ((u32)in[0] << 24) | ((u32)in[1] << 16) | \
+          ((u32)in[2] << 8) | (u32)in[3];
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline u32 buf_get_le32(const void *_buf)
+ {
+   const byte *in = _buf;
+   return ((u32)in[3] << 24) | ((u32)in[2] << 16) | \
+          ((u32)in[1] << 8) | (u32)in[0];
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline void buf_put_be32(void *_buf, u32 val)
+ {
+@@ -262,7 +262,7 @@ static inline void buf_put_be32(void *_b
+   out[1] = val >> 16;
+   out[2] = val >> 8;
+   out[3] = val;
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline void buf_put_le32(void *_buf, u32 val)
+ {
+@@ -271,7 +271,7 @@ static inline void buf_put_le32(void *_b
+   out[2] = val >> 16;
+   out[1] = val >> 8;
+   out[0] = val;
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ #ifdef HAVE_U64_TYPEDEF
+ /* Functions for loading and storing unaligned u64 values of different
+@@ -283,7 +283,7 @@ static inline u64 buf_get_be64(const voi
+          ((u64)in[2] << 40) | ((u64)in[3] << 32) | \
+          ((u64)in[4] << 24) | ((u64)in[5] << 16) | \
+          ((u64)in[6] << 8) | (u64)in[7];
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline u64 buf_get_le64(const void *_buf)
+ {
+@@ -292,7 +292,7 @@ static inline u64 buf_get_le64(const voi
+          ((u64)in[5] << 40) | ((u64)in[4] << 32) | \
+          ((u64)in[3] << 24) | ((u64)in[2] << 16) | \
+          ((u64)in[1] << 8) | (u64)in[0];
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline void buf_put_be64(void *_buf, u64 val)
+ {
+@@ -305,7 +305,7 @@ static inline void buf_put_be64(void *_b
+   out[5] = val >> 16;
+   out[6] = val >> 8;
+   out[7] = val;
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline void buf_put_le64(void *_buf, u64 val)
+ {
+@@ -318,7 +318,7 @@ static inline void buf_put_le64(void *_b
+   out[2] = val >> 16;
+   out[1] = val >> 8;
+   out[0] = val;
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ #endif /*HAVE_U64_TYPEDEF*/
+ 
+ #else /*BUFHELP_FAST_UNALIGNED_ACCESS*/
+@@ -328,24 +328,24 @@ static inline void buf_put_le64(void *_b
+ static inline u32 buf_get_be32(const void *_buf)
+ {
+   return be_bswap32(*(const u32 *)_buf);
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline u32 buf_get_le32(const void *_buf)
+ {
+   return le_bswap32(*(const u32 *)_buf);
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline void buf_put_be32(void *_buf, u32 val)
+ {
+   u32 *out = _buf;
+   *out = be_bswap32(val);
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline void buf_put_le32(void *_buf, u32 val)
+ {
+   u32 *out = _buf;
+   *out = le_bswap32(val);
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ #ifdef HAVE_U64_TYPEDEF
+ /* Functions for loading and storing unaligned u64 values of different
+@@ -353,24 +353,24 @@ static inline void buf_put_le32(void *_b
+ static inline u64 buf_get_be64(const void *_buf)
+ {
+   return be_bswap64(*(const u64 *)_buf);
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline u64 buf_get_le64(const void *_buf)
+ {
+   return le_bswap64(*(const u64 *)_buf);
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline void buf_put_be64(void *_buf, u64 val)
+ {
+   u64 *out = _buf;
+   *out = be_bswap64(val);
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ 
+ static inline void buf_put_le64(void *_buf, u64 val)
+ {
+   u64 *out = _buf;
+   *out = le_bswap64(val);
+-}
++} __attribute__ ((optimize("no-strict-aliasing")))
+ #endif /*HAVE_U64_TYPEDEF*/
+ 
+ #endif /*BUFHELP_FAST_UNALIGNED_ACCESS*/
diff --git a/libgcrypt.spec b/libgcrypt.spec
index 418dbc8..08030d0 100644
--- a/libgcrypt.spec
+++ b/libgcrypt.spec
@@ -1,6 +1,6 @@
 Name: libgcrypt
 Version: 1.6.3
-Release: 1%{?dist}
+Release: 2%{?dist}
 URL: http://www.gnupg.org/
 Source0: libgcrypt-%{version}-hobbled.tar.xz
 # The original libgcrypt sources now contain potentially patented ECC
@@ -43,6 +43,8 @@ Patch19: libgcrypt-1.6.2-fips-test.patch
 Patch20: libgcrypt-1.6.3-rsa-fips-keygen.patch
 # update the selftests for new FIPS requirements
 Patch22: libgcrypt-1.6.2-fips-reqs.patch
+# do not use strict aliasing for bufhelp functions
+Patch23: libgcrypt-1.6.3-aliasing.patch
 
 %define gcrylibdir %{_libdir}
 
@@ -91,6 +93,7 @@ applications using libgcrypt.
 %patch19 -p1 -b .fips-test
 %patch20 -p1 -b .fips-keygen
 %patch22 -p1 -b .fips-reqs
+%patch23 -p1 -b .aliasing
 cp %{SOURCE4} cipher/
 cp %{SOURCE5} %{SOURCE6} tests/
 
@@ -201,6 +204,9 @@ exit 0
 %license COPYING
 
 %changelog
+* Fri Mar 13 2015 Tomáš Mráz <tmraz@redhat.com> 1.6.3-2
+- do not use strict aliasing for bufhelp functions (#1201219)
+
 * Fri Mar  6 2015 Tomáš Mráz <tmraz@redhat.com> 1.6.3-1
 - new upstream version