diff --git a/include/mbedtls/chacha20.h b/include/mbedtls/chacha20.h
index ab10a96..d23618e 100644
--- a/include/mbedtls/chacha20.h
+++ b/include/mbedtls/chacha20.h
@@ -121,7 +121,7 @@
  *                  output pointers are NULL.
  *                  Otherwise, 0 is returned to indicate success.
  */
-int mbedtls_chacha20_process( mbedtls_chacha20_context *ctx,
+int mbedtls_chacha20_update( mbedtls_chacha20_context *ctx,
                               size_t size,
                               const unsigned char *input,
                               unsigned char *output );
diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index 3ee2ab7..c5a50c0 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -86,6 +86,7 @@
     MBEDTLS_CIPHER_ID_CAMELLIA,  /**< The Camellia cipher. */
     MBEDTLS_CIPHER_ID_BLOWFISH,  /**< The Blowfish cipher. */
     MBEDTLS_CIPHER_ID_ARC4,      /**< The RC4 cipher. */
+    MBEDTLS_CIPHER_ID_CHACHA20,  /**< The Chacha20 cipher. */
 } mbedtls_cipher_id_t;
 
 /**
@@ -145,6 +146,7 @@
     MBEDTLS_CIPHER_CAMELLIA_128_CCM,     /**< Camellia cipher with 128-bit CCM mode. */
     MBEDTLS_CIPHER_CAMELLIA_192_CCM,     /**< Camellia cipher with 192-bit CCM mode. */
     MBEDTLS_CIPHER_CAMELLIA_256_CCM,     /**< Camellia cipher with 256-bit CCM mode. */
+    MBEDTLS_CIPHER_CHACHA20,             /**< Chacha20 stream cipher. */
 } mbedtls_cipher_type_t;
 
 /** Supported cipher modes. */
@@ -190,7 +192,7 @@
 /** Maximum length of any IV, in Bytes. */
 #define MBEDTLS_MAX_IV_LENGTH      16
 /** Maximum block size of any cipher, in Bytes. */
-#define MBEDTLS_MAX_BLOCK_LENGTH   16
+#define MBEDTLS_MAX_BLOCK_LENGTH   64
 
 /**
  * Base cipher information (opaque struct).