diff --git a/conform/data/threads.h-data b/conform/data/threads.h-data
index bc2d857..bb5ca75 100644
--- a/conform/data/threads.h-data
+++ b/conform/data/threads.h-data
@@ -6,8 +6,13 @@ constant thrd_error
 constant thrd_nomem
 constant thrd_timedout
 
+constant mtx_plain
+constant mtx_recursive
+constant mtx_timed
+
 type thrd_t
 type thrd_start_t
+type mtx_t
 
 function int thrd_create (thrd_t*, thrd_start_t, void*)
 function int thrd_equal (thrd_t, thrd_t)
@@ -18,6 +23,13 @@ function int thrd_detach (thrd_t)
 function int thrd_join (thrd_t, int*)
 function void thrd_yield (void)
 
+function int mtx_init (mtx_t*, int)
+function int mtx_lock (mtx_t*)
+function int mtx_timedlock (mtx_t*, const struct timespec*)
+function int mtx_trylock (mtx_t*)
+function int mtx_unlock (mtx_t*)
+function void mtx_destroy (mtx_t*)
+
 #include "time.h-data"
 
 #endif
diff --git a/nptl/Makefile b/nptl/Makefile
index e79fb97..157ebe1 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -140,7 +140,9 @@ libpthread-routines = nptl-init vars events version pt-interp \
 		      pthread_setname pthread_getname \
 		      pthread_setattr_default_np pthread_getattr_default_np \
 		      thrd_create thrd_current thrd_detach thrd_equal \
-		      thrd_exit thrd_join thrd_sleep thrd_yield
+		      thrd_exit thrd_join thrd_sleep thrd_yield \
+		      mtx_destroy mtx_init mtx_lock mtx_timedlock \
+		      mtx_trylock mtx_unlock
 #		      pthread_setuid pthread_seteuid pthread_setreuid \
 #		      pthread_setresuid \
 #		      pthread_setgid pthread_setegid pthread_setregid \
diff --git a/nptl/Versions b/nptl/Versions
index 703f129..2fd362f 100644
--- a/nptl/Versions
+++ b/nptl/Versions
@@ -268,7 +268,8 @@ libpthread {
   # C11 thread symbols.
   GLIBC_2.26 {
     thrd_create; thrd_current; thrd_detach; thrd_equal; thrd_exit; thrd_join;
-    thrd_sleep; thrd_yield;
+    thrd_sleep; thrd_yield; mtx_init; mtx_lock; mtx_timedlock; mtx_trylock;
+    mtx_unlock; mtx_destroy;
   }
 
   GLIBC_PRIVATE {
diff --git a/nptl/mtx_destroy.c b/nptl/mtx_destroy.c
new file mode 100644
index 0000000..1fcc534
--- /dev/null
+++ b/nptl/mtx_destroy.c
@@ -0,0 +1,27 @@
+/* C11 threads mutex destroy implementation.
+   Copyright (C) 2017 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/>.  */
+
+#include "thrd_priv.h"
+#include "pthreadP.h"
+
+/* Destroy the mutex object pointed by mutex.  */
+void
+mtx_destroy (mtx_t *mutex)
+{
+  __pthread_mutex_destroy ((pthread_mutex_t *) mutex);
+}
diff --git a/nptl/mtx_init.c b/nptl/mtx_init.c
new file mode 100644
index 0000000..44ac329
--- /dev/null
+++ b/nptl/mtx_init.c
@@ -0,0 +1,48 @@
+/* C11 threads mutex initialization implementation.
+   Copyright (C) 2017 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/>.  */
+
+#include "thrd_priv.h"
+
+/* Creates a new mutex object with type type.  If successful the new object
+   is pointed by mutex.  */
+int
+mtx_init (mtx_t *mutex, int type)
+{
+  pthread_mutexattr_t attr;
+
+  __pthread_mutexattr_init (&attr);
+
+  /* Another possible solution would be to set the flags directly in
+     mutex object. */
+  switch (type)
+  {
+    case mtx_plain | mtx_recursive:
+    case mtx_timed | mtx_recursive:
+      __pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_RECURSIVE);
+      break;
+    case mtx_plain:
+    case mtx_timed: /* No difference between both in standard */
+    default:
+      __pthread_mutexattr_settype (&attr, PTHREAD_MUTEX_NORMAL);
+      break;
+  }
+
+  int err_code = __pthread_mutex_init ((pthread_mutex_t *) mutex, &attr);
+  /* pthread_mutexattr_destroy implementation is a noop.  */
+  return thrd_err_map (err_code);
+}
diff --git a/nptl/mtx_lock.c b/nptl/mtx_lock.c
new file mode 100644
index 0000000..bd4c530
--- /dev/null
+++ b/nptl/mtx_lock.c
@@ -0,0 +1,28 @@
+/* C11 threads mutex lock implementation.
+   Copyright (C) 2017 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/>.  */
+
+#include "thrd_priv.h"
+
+/* Block the current thread until the mutex pointed to by mutex is
+   unlocked.  In that case current thread will not be blocked.  */
+int
+mtx_lock (mtx_t *mutex)
+{
+  int err_code = __pthread_mutex_lock ((pthread_mutex_t *) mutex);
+  return thrd_err_map (err_code);
+}
diff --git a/nptl/mtx_timedlock.c b/nptl/mtx_timedlock.c
new file mode 100644
index 0000000..3770d5c
--- /dev/null
+++ b/nptl/mtx_timedlock.c
@@ -0,0 +1,31 @@
+/* C11 threads mutex timed lock implementation.
+   Copyright (C) 2017 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/>.  */
+
+#include "thrd_priv.h"
+
+/* Block the current thread until the mutex pointed by mutex is unlocked
+   or time pointed by time_point is reached.  In case the mutex is unlocked
+   current thread will not be blocked.  */
+int
+mtx_timedlock (mtx_t *restrict mutex,
+	       const struct timespec *restrict time_point)
+{
+  int err_code = __pthread_mutex_timedlock ((pthread_mutex_t *)mutex,
+					    time_point);
+  return thrd_err_map (err_code);
+}
diff --git a/nptl/mtx_trylock.c b/nptl/mtx_trylock.c
new file mode 100644
index 0000000..406229a
--- /dev/null
+++ b/nptl/mtx_trylock.c
@@ -0,0 +1,29 @@
+/* C11 threads mutex try lock implementation.
+   Copyright (C) 2017 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/>.  */
+
+#include "thrd_priv.h"
+
+/* Try to lock the mutex pointed by mutex without blocking.  If the mutex
+   is free the current threads takes control of it, otherwise it returns
+   immediately.  */
+int
+mtx_trylock (mtx_t *mutex)
+{
+  int err_code = __pthread_mutex_trylock ((pthread_mutex_t *) mutex);
+  return thrd_err_map (err_code);
+}
diff --git a/nptl/mtx_unlock.c b/nptl/mtx_unlock.c
new file mode 100644
index 0000000..d5f9c32
--- /dev/null
+++ b/nptl/mtx_unlock.c
@@ -0,0 +1,28 @@
+/* C11 threads mutex unlock implementation.
+   Copyright (C) 2017 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/>.  */
+
+#include "thrd_priv.h"
+
+/* Unlock the mutex pointed by mutex.  It may potentially awake other
+   threads waiting on this mutex.  */
+int
+mtx_unlock (mtx_t *mutex)
+{
+  int err_code = __pthread_mutex_unlock ((pthread_mutex_t *) mutex);
+  return thrd_err_map (err_code);
+}
diff --git a/sysdeps/nptl/threads.h b/sysdeps/nptl/threads.h
index a487ad3..f6d4f1a 100644
--- a/sysdeps/nptl/threads.h
+++ b/sysdeps/nptl/threads.h
@@ -40,6 +40,21 @@ enum
   thrd_timedout = 4
 };
 
+/* Mutex types.  */
+enum
+{
+  mtx_plain     = 0,
+  mtx_recursive = 1,
+  mtx_timed     = 2
+};
+
+typedef union
+{
+  struct __pthread_mutex_s __data;
+  char __size[__SIZEOF_PTHREAD_MUTEX_T];
+  long int __align;
+} mtx_t;
+
 /* Threads functions.  */
 
 /* Create a new thread executing the function __func.  Arguments to __func
@@ -86,6 +101,35 @@ thrd_equal (thrd_t __thread1, thrd_t __thread2)
 }
 #endif
 
+
+/* Mutex functions.  */
+
+/* Creates a new mutex object with type __type.  If successful the new
+   object is pointed by __mutex.  */
+extern int mtx_init (mtx_t *__mutex, int __type);
+
+/* Block the current thread until the mutex pointed to by __mutex is
+   unlocked.  In that case current thread will not be blocked.  */
+extern int mtx_lock (mtx_t *__mutex);
+
+/* Block the current thread until the mutex pointed by __mutex is unlocked
+   or time pointed by __time_point is reached.  In case the mutex is unlock,
+   the current thread will not be blocked.  */
+extern int mtx_timedlock (mtx_t *__restrict __mutex,
+			  const struct timespec *__restrict __time_point);
+
+/* Try to lock the mutex pointed by __mutex without blocking.  If the mutex
+   is free the current threads takes control of it, otherwise it returns
+   immediately.  */
+extern int mtx_trylock (mtx_t *__mutex);
+
+/* Unlock the mutex pointed by __mutex.  It may potentially awake other
+   threads waiting on this mutex.  */
+extern int mtx_unlock (mtx_t *__mutex);
+
+/* Destroy the mutex object pointed by __mutex.  */
+extern void mtx_destroy (mtx_t *__mutex);
+
 __END_DECLS
 
 #endif /* _THREADS_H */
