diff --git a/include/mbedtls/pkcs5.h b/include/mbedtls/pkcs5.h
index 5a765e0..f46be12 100644
--- a/include/mbedtls/pkcs5.h
+++ b/include/mbedtls/pkcs5.h
@@ -61,7 +61,7 @@
  * \param datalen    length of data
  * \param output     output buffer
  *
- * \returns        0 on success, or a POLARSSL_ERR_xxx code if verification fails.
+ * \returns        0 on success, or a POLARSSL_ERR_XXX code if verification fails.
  */
 int pkcs5_pbes2( const asn1_buf *pbe_params, int mode,
                  const unsigned char *pwd,  size_t pwdlen,
@@ -80,7 +80,7 @@
  * \param key_length            Length of generated key
  * \param output   Generated key. Must be at least as big as key_length
  *
- * \returns        0 on success, or a POLARSSL_ERR_xxx code if verification fails.
+ * \returns        0 on success, or a POLARSSL_ERR_XXX code if verification fails.
  */
 int pkcs5_pbkdf2_hmac( md_context_t *ctx, const unsigned char *password,
                        size_t plen, const unsigned char *salt, size_t slen,