diff --git a/include/mbedtls/des.h b/include/mbedtls/des.h
index 5ca2ecf..37032d3 100644
--- a/include/mbedtls/des.h
+++ b/include/mbedtls/des.h
@@ -19,6 +19,11 @@
  *  limitations under the License.
  *
  *  This file is part of mbed TLS (https://tls.mbed.org)
+ *
+ * \warning   DES is considered a weak cipher and its use constitutes a
+ *            security risk. We recommend considering stronger ciphers
+ *            instead.
+ *
  */
 #ifndef MBEDTLS_DES_H
 #define MBEDTLS_DES_H
@@ -49,6 +54,10 @@
 
 /**
  * \brief          DES context structure
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 typedef struct
 {
@@ -69,6 +78,10 @@
  * \brief          Initialize DES context
  *
  * \param ctx      DES context to be initialized
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 void mbedtls_des_init( mbedtls_des_context *ctx );
 
@@ -76,6 +89,10 @@
  * \brief          Clear DES context
  *
  * \param ctx      DES context to be cleared
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 void mbedtls_des_free( mbedtls_des_context *ctx );
 
@@ -100,6 +117,10 @@
  *                 a parity bit to allow verification.
  *
  * \param key      8-byte secret key
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 void mbedtls_des_key_set_parity( unsigned char key[MBEDTLS_DES_KEY_SIZE] );
 
@@ -112,6 +133,10 @@
  * \param key      8-byte secret key
  *
  * \return         0 is parity was ok, 1 if parity was not correct.
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 int mbedtls_des_key_check_key_parity( const unsigned char key[MBEDTLS_DES_KEY_SIZE] );
 
@@ -121,6 +146,10 @@
  * \param key      8-byte secret key
  *
  * \return         0 if no weak key was found, 1 if a weak key was identified.
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 int mbedtls_des_key_check_weak( const unsigned char key[MBEDTLS_DES_KEY_SIZE] );
 
@@ -131,6 +160,10 @@
  * \param key      8-byte secret key
  *
  * \return         0
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 int mbedtls_des_setkey_enc( mbedtls_des_context *ctx, const unsigned char key[MBEDTLS_DES_KEY_SIZE] );
 
@@ -141,6 +174,10 @@
  * \param key      8-byte secret key
  *
  * \return         0
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 int mbedtls_des_setkey_dec( mbedtls_des_context *ctx, const unsigned char key[MBEDTLS_DES_KEY_SIZE] );
 
@@ -196,6 +233,10 @@
  * \param output   64-bit output block
  *
  * \return         0 if successful
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 int mbedtls_des_crypt_ecb( mbedtls_des_context *ctx,
                     const unsigned char input[8],
@@ -219,6 +260,10 @@
  * \param iv       initialization vector (updated after use)
  * \param input    buffer holding the input data
  * \param output   buffer holding the output data
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 int mbedtls_des_crypt_cbc( mbedtls_des_context *ctx,
                     int mode,
@@ -277,6 +322,10 @@
  *
  * \param SK       Round keys
  * \param key      Base key
+ *
+ * \warning        DES is considered a weak cipher and its use constitutes a
+ *                 security risk. We recommend considering stronger ciphers
+ *                 instead.
  */
 void mbedtls_des_setkey( uint32_t SK[32],
                          const unsigned char key[MBEDTLS_DES_KEY_SIZE] );