diff --git a/include/mbedtls/sha512.h b/include/mbedtls/sha512.h
index bf40e4b..34a90b5 100644
--- a/include/mbedtls/sha512.h
+++ b/include/mbedtls/sha512.h
@@ -272,7 +272,7 @@
  * \param ilen     The length of the input data in Bytes.
  * \param output   The SHA-384 or SHA-512 checksum result. This must
  *                 be a writable buffer of length \c 64 Bytes.
- * \param is384    Determines which function to use. This must be eiher
+ * \param is384    Determines which function to use. This must be either
  *                 \c 0 for SHA-512, or \c 1 for SHA-384.
  */
 MBEDTLS_DEPRECATED void mbedtls_sha512( const unsigned char *input,