diff --git a/posix/Makefile b/posix/Makefile
index 15e8818..32d4146 100644
--- a/posix/Makefile
+++ b/posix/Makefile
@@ -29,7 +29,7 @@ headers := sys/utsname.h sys/times.h sys/wait.h
sys/types.h unistd.h      \
    bits/local_lim.h tar.h bits/utsname.h bits/confname.h      \
    bits/waitflags.h bits/waitstatus.h sys/unistd.h sched.h      \
    bits/sched.h re_comp.h wait.h bits/environments.h cpio.h      \
-   sys/sysmacros.h spawn.h bits/unistd.h
+   sys/sysmacros.h spawn.h bits/unistd.h bits/pthreadsharedtypes.h

 routines :=      \
  uname      \
diff --git a/sysdeps/x86/bits/pthreadsharedtypes.h
b/sysdeps/x86/bits/pthreadsharedtypes.h
new file mode 100644
index 0000000..d9454ec
--- /dev/null
+++ b/sysdeps/x86/bits/pthreadsharedtypes.h
@@ -0,0 +1,131 @@
+/* Copyright (C) 2002-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This header contains the declaration of pthread_mutex_t and
+   pthread_cond_t needed by C11 types mtx_t and cnd_t. */
+
+#ifndef _BITS_PTHREADSHAREDTYPES_H
+#define _BITS_PTHREADSHAREDTYPES_H 1
+
+#include <bits/wordsize.h>
+
+#ifdef __x86_64__
+# if __WORDSIZE == 64
+#  define __SIZEOF_PTHREAD_MUTEX_T 40
+#  define __SIZEOF_PTHREAD_COND_T 48
+# else
+#  define __SIZEOF_PTHREAD_MUTEX_T 32
+#  define __SIZEOF_PTHREAD_COND_T 48
+# endif
+#else
+# define __SIZEOF_PTHREAD_MUTEX_T 24
+# define __SIZEOF_PTHREAD_COND_T 48
+#endif
+
+#ifdef __x86_64__
+typedef struct __pthread_internal_list
+{
+  struct __pthread_internal_list *__prev;
+  struct __pthread_internal_list *__next;
+} __pthread_list_t;
+#else
+typedef struct __pthread_internal_slist
+{
+  struct __pthread_internal_slist *__next;
+} __pthread_slist_t;
+#endif
+
+
+/* Data structure for mutex handling. */
+
+#ifdef __x86_64__
+
+# define __PTHREAD_MUTEX_HAVE_PREV 1
+/* Mutex __spins initializer used by PTHREAD_MUTEX_INITIALIZER.  */
+# define __PTHREAD_SPINS             0, 0
+
+
+# define __PTHREAD_MUTEX_T_CONTENT            \
+  struct __pthread_mutex_s                    \
+  {                                           \
+    int __lock;                               \
+    unsigned int __count;                     \
+    int __owner;                              \
+    unsigned int __nusers;                    \
+    /* KIND must stay at this position in the structure to maintain
+       binary compatibility.  */              \
+    int __kind;                               \
+    short __spins;                            \
+    short __elision;                          \
+    __pthread_list_t __list;                  \
+  } __data;                                   \
+  char __size[__SIZEOF_PTHREAD_MUTEX_T];      \
+  long int __align;
+
+
+
+#else
+
+# define __spins __elision_data.__espins
+# define __elision __elision_data.__elision
+# define __PTHREAD_SPINS         { 0, 0 }
+
+
+# define __PTHREAD_MUTEX_T_CONTENT         \
+  struct pthread_mutex_s                   \
+  {                                        \
+    int __lock;                            \
+    unsigned int __count;                  \
+    int __owner;                           \
+    /* KIND must stay at this position. */ \
+    int __kind;                            \
+    unsigned int __nusers;                 \
+    __extension__ union                    \
+    {                                      \
+      struct                               \
+      {                                    \
+ short __espins;                        \
+ short __elision;                       \
+      } __elision_data;                    \
+      __pthread_slist_t __list;            \
+    };                                     \
+  } __data;                                \
+  char __size[__SIZEOF_PTHREAD_MUTEX_T];   \
+  long int __align;
+
+#endif
+
+
+/* Data structure for conditional variable handling */
+
+#define __PTHREAD_COND_T_CONTENT                          \
+  struct                                                  \
+  {                                                       \
+    int __lock;                                           \
+    unsigned int __futex;                                 \
+    __extension__ unsigned long long int __total_seq;     \
+    __extension__ unsigned long long int __wakeup_seq;    \
+    __extension__ unsigned long long int __woken_seq;     \
+    void *__mutex;                                        \
+    unsigned int __nwaiters;                              \
+    unsigned int __broadcast_seq;                         \
+  } __data;                                               \
+  char __size[__SIZEOF_PTHREAD_COND_T];                   \
+  __extension__ long long int __align;
+
+
+#endif /* bits/pthreadsharedtypes.h */
diff --git a/sysdeps/x86/bits/pthreadtypes.h b/sysdeps/x86/bits/pthreadtypes.h
index 4460615..f900cef 100644
--- a/sysdeps/x86/bits/pthreadtypes.h
+++ b/sysdeps/x86/bits/pthreadtypes.h
@@ -19,13 +19,12 @@
 #define _BITS_PTHREADTYPES_H 1

 #include <bits/wordsize.h>
+#include <bits/pthreadsharedtypes.h>

 #ifdef __x86_64__
 # if __WORDSIZE == 64
 #  define __SIZEOF_PTHREAD_ATTR_T 56
-#  define __SIZEOF_PTHREAD_MUTEX_T 40
 #  define __SIZEOF_PTHREAD_MUTEXATTR_T 4
-#  define __SIZEOF_PTHREAD_COND_T 48
 #  define __SIZEOF_PTHREAD_CONDATTR_T 4
 #  define __SIZEOF_PTHREAD_RWLOCK_T 56
 #  define __SIZEOF_PTHREAD_RWLOCKATTR_T 8
@@ -33,9 +32,7 @@
 #  define __SIZEOF_PTHREAD_BARRIERATTR_T 4
 # else
 #  define __SIZEOF_PTHREAD_ATTR_T 32
-#  define __SIZEOF_PTHREAD_MUTEX_T 32
 #  define __SIZEOF_PTHREAD_MUTEXATTR_T 4
-#  define __SIZEOF_PTHREAD_COND_T 48
 #  define __SIZEOF_PTHREAD_CONDATTR_T 4
 #  define __SIZEOF_PTHREAD_RWLOCK_T 44
 #  define __SIZEOF_PTHREAD_RWLOCKATTR_T 8
@@ -44,9 +41,7 @@
 # endif
 #else
 # define __SIZEOF_PTHREAD_ATTR_T 36
-# define __SIZEOF_PTHREAD_MUTEX_T 24
 # define __SIZEOF_PTHREAD_MUTEXATTR_T 4
-# define __SIZEOF_PTHREAD_COND_T 48
 # define __SIZEOF_PTHREAD_CONDATTR_T 4
 # define __SIZEOF_PTHREAD_RWLOCK_T 32
 # define __SIZEOF_PTHREAD_RWLOCKATTR_T 8
@@ -71,60 +66,11 @@ typedef union pthread_attr_t pthread_attr_t;
 #endif


-#ifdef __x86_64__
-typedef struct __pthread_internal_list
-{
-  struct __pthread_internal_list *__prev;
-  struct __pthread_internal_list *__next;
-} __pthread_list_t;
-#else
-typedef struct __pthread_internal_slist
-{
-  struct __pthread_internal_slist *__next;
-} __pthread_slist_t;
-#endif
-
-
 /* Data structures for mutex handling.  The structure of the attribute
    type is not exposed on purpose.  */
 typedef union
 {
-  struct __pthread_mutex_s
-  {
-    int __lock;
-    unsigned int __count;
-    int __owner;
-#ifdef __x86_64__
-    unsigned int __nusers;
-#endif
-    /* KIND must stay at this position in the structure to maintain
-       binary compatibility.  */
-    int __kind;
-#ifdef __x86_64__
-    short __spins;
-    short __elision;
-    __pthread_list_t __list;
-# define __PTHREAD_MUTEX_HAVE_PREV 1
-/* Mutex __spins initializer used by PTHREAD_MUTEX_INITIALIZER.  */
-# define __PTHREAD_SPINS             0, 0
-#else
-    unsigned int __nusers;
-    __extension__ union
-    {
-      struct
-      {
- short __espins;
- short __elision;
-# define __spins __elision_data.__espins
-# define __elision __elision_data.__elision
-# define __PTHREAD_SPINS         { 0, 0 }
-      } __elision_data;
-      __pthread_slist_t __list;
-    };
-#endif
-  } __data;
-  char __size[__SIZEOF_PTHREAD_MUTEX_T];
-  long int __align;
+ __PTHREAD_MUTEX_T_CONTENT
 } pthread_mutex_t;

 typedef union
@@ -138,19 +84,7 @@ typedef union
    the attribute type is not exposed on purpose.  */
 typedef union
 {
-  struct
-  {
-    int __lock;
-    unsigned int __futex;
-    __extension__ unsigned long long int __total_seq;
-    __extension__ unsigned long long int __wakeup_seq;
-    __extension__ unsigned long long int __woken_seq;
-    void *__mutex;
-    unsigned int __nwaiters;
-    unsigned int __broadcast_seq;
-  } __data;
-  char __size[__SIZEOF_PTHREAD_COND_T];
-  __extension__ long long int __align;
+ __PTHREAD_COND_T_CONTENT
 } pthread_cond_t;

 typedef union
diff --git a/sysdeps/x86/bits/threadstypes.h b/sysdeps/x86/bits/threadstypes.h
new file mode 100644
index 0000000..6ae5e0f
--- /dev/null
+++ b/sysdeps/x86/bits/threadstypes.h
@@ -0,0 +1,41 @@
+/* Copyright (C) 2002-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* Contains declaration of C11 types: mtx_t and cnd_t. */
+
+
+#ifndef _BITS_THREADSTYPES_H
+#define _BITS_THREADSTYPES_H 1
+
+#include <bits/pthreadsharedtypes.h>
+
+/* mtx_t is a copy of pthread_mutex_t. */
+
+typedef union
+{
+ __PTHREAD_MUTEX_T_CONTENT
+} mtx_t;
+
+
+/* cnd_t is a copy of pthread_cond_t. */
+
+typedef union
+{
+ __PTHREAD_COND_T_CONTENT
+} cnd_t;
+
+#endif /* bits/threadstypes.h */
