diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index 94ee58a..e280dbb 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -522,10 +522,6 @@
  * \brief      This function performs an AES-CTR encryption or decryption
  *             operation.
  *
- *             This function performs the operation defined in the \p mode
- *             parameter (encrypt/decrypt), on the input data buffer
- *             defined in the \p input parameter.
- *
  *             Due to the nature of CTR, you must use the same key schedule
  *             for both encryption and decryption operations. Therefore, you
  *             must use the context initialized with mbedtls_aes_setkey_enc()
diff --git a/include/mbedtls/sha256.h b/include/mbedtls/sha256.h
index cccd5c4..d01f2eb 100644
--- a/include/mbedtls/sha256.h
+++ b/include/mbedtls/sha256.h
@@ -269,6 +269,9 @@
  *                 a writable buffer of length \c 32 Bytes.
  * \param is224    Determines which function to use. This must be either
  *                 \c 0 for SHA-256, or \c 1 for SHA-224.
+ *
+ * \return         \c 0 on success.
+ * \return         A negative error code on failure.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha256( const unsigned char *input,
                                         size_t ilen,