diff --git a/include/mbedcrypto/threading.h b/include/mbedcrypto/threading.h
new file mode 100644
index 0000000..8e14f6b
--- /dev/null
+++ b/include/mbedcrypto/threading.h
@@ -0,0 +1,111 @@
+/**
+ * \file threading.h
+ *
+ * \brief Threading abstraction layer
+ */
+/*
+ *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of Mbed Crypto (https://tls.mbed.org)
+ */
+#ifndef MBEDCRYPTO_THREADING_H
+#define MBEDCRYPTO_THREADING_H
+
+#if !defined(MBEDCRYPTO_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDCRYPTO_CONFIG_FILE
+#endif
+
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define MBEDCRYPTO_ERR_THREADING_FEATURE_UNAVAILABLE         -0x001A  /**< The selected feature is not available. */
+#define MBEDCRYPTO_ERR_THREADING_BAD_INPUT_DATA              -0x001C  /**< Bad input parameters to function. */
+#define MBEDCRYPTO_ERR_THREADING_MUTEX_ERROR                 -0x001E  /**< Locking / unlocking / free failed with error code. */
+
+#if defined(MBEDCRYPTO_THREADING_PTHREAD)
+#include <pthread.h>
+typedef struct
+{
+    pthread_mutex_t mutex;
+    char is_valid;
+} mbedcrypto_threading_mutex_t;
+#endif
+
+#if defined(MBEDCRYPTO_THREADING_ALT)
+/* You should define the mbedcrypto_threading_mutex_t type in your header */
+#include "threading_alt.h"
+
+/**
+ * \brief           Set your alternate threading implementation function
+ *                  pointers and initialize global mutexes. If used, this
+ *                  function must be called once in the main thread before any
+ *                  other Mbed Crypto function is called, and
+ *                  mbedcrypto_threading_free_alt() must be called once in the main
+ *                  thread after all other Mbed Crypto functions.
+ *
+ * \note            mutex_init() and mutex_free() don't return a status code.
+ *                  If mutex_init() fails, it should leave its argument (the
+ *                  mutex) in a state such that mutex_lock() will fail when
+ *                  called with this argument.
+ *
+ * \param mutex_init    the init function implementation
+ * \param mutex_free    the free function implementation
+ * \param mutex_lock    the lock function implementation
+ * \param mutex_unlock  the unlock function implementation
+ */
+void mbedcrypto_threading_set_alt( void (*mutex_init)( mbedcrypto_threading_mutex_t * ),
+                       void (*mutex_free)( mbedcrypto_threading_mutex_t * ),
+                       int (*mutex_lock)( mbedcrypto_threading_mutex_t * ),
+                       int (*mutex_unlock)( mbedcrypto_threading_mutex_t * ) );
+
+/**
+ * \brief               Free global mutexes.
+ */
+void mbedcrypto_threading_free_alt( void );
+#endif /* MBEDCRYPTO_THREADING_ALT */
+
+#if defined(MBEDCRYPTO_THREADING_C)
+/*
+ * The function pointers for mutex_init, mutex_free, mutex_ and mutex_unlock
+ *
+ * All these functions are expected to work or the result will be undefined.
+ */
+extern void (*mbedcrypto_mutex_init)( mbedcrypto_threading_mutex_t *mutex );
+extern void (*mbedcrypto_mutex_free)( mbedcrypto_threading_mutex_t *mutex );
+extern int (*mbedcrypto_mutex_lock)( mbedcrypto_threading_mutex_t *mutex );
+extern int (*mbedcrypto_mutex_unlock)( mbedcrypto_threading_mutex_t *mutex );
+
+/*
+ * Global mutexes
+ */
+#if defined(MBEDCRYPTO_FS_IO)
+extern mbedcrypto_threading_mutex_t mbedcrypto_threading_readdir_mutex;
+#endif
+#if defined(MBEDCRYPTO_HAVE_TIME_DATE)
+extern mbedcrypto_threading_mutex_t mbedcrypto_threading_gmtime_mutex;
+#endif
+#endif /* MBEDCRYPTO_THREADING_C */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* threading.h */