diff --git a/include/mbedtls/chachapoly.h b/include/mbedtls/chachapoly.h
index 3f4318f..2b49402 100644
--- a/include/mbedtls/chachapoly.h
+++ b/include/mbedtls/chachapoly.h
@@ -158,7 +158,7 @@
  * \param ctx       The ChaCha20-Poly1305 context. This must be initialized
  *                  and bound to a key.
  * \param nonce     The nonce/IV to use for the message.
- *                  This must be a redable buffer of length \c 12 Bytes.
+ *                  This must be a readable buffer of length \c 12 Bytes.
  * \param mode      The operation to perform: #MBEDTLS_CHACHAPOLY_ENCRYPT or
  *                  #MBEDTLS_CHACHAPOLY_DECRYPT (discouraged, see warning).
  *