diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 6e1bb3a..5915eae 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -3230,18 +3230,34 @@
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
 /**
- * \brief          Return the peer certificate from the current connection
+ * \brief          Return the peer certificate from the current connection.
  *
- *                 Note: Can be NULL in case no certificate was sent during
- *                 the handshake. Different calls for the same connection can
- *                 return the same or different pointers for the same
- *                 certificate and even a different certificate altogether.
- *                 The peer cert CAN change in a single connection if
- *                 renegotiation is performed.
+ *                 For ciphersuites not using certificate-based peer
+ *                 authentication (such as PSK-based ciphersuites), no
+ *                 peer certificate is available, and this function returns
+ *                 \c NULL.
  *
- * \param ssl      SSL context
+ * \param  ssl     The SSL context to use. This must be initialized and setup.
  *
- * \return         the current peer certificate
+ * \return         The current peer certificate, or \c NULL if
+ *                 none is available. It is owned by the SSL context
+ *                 and valid only until the next call to the SSL API.
+ *
+ * \note           For one-time inspection of the peer's certificate during
+ *                 the handshake, consider registering an X.509 CRT verification
+ *                 callback through mbedtls_ssl_conf_verify() instead of calling
+ *                 this function. Using mbedtls_ssl_conf_verify() also comes at
+ *                 the benefit of allowing you to influence the verification
+ *                 process, for example by masking expected and tolerated
+ *                 verification failures.
+ *
+ * \warning        You must not use the pointer returned by this function
+ *                 after any further call to the SSL API, including
+ *                 mbedtls_ssl_read() and mbedtls_ssl_write(); this is
+ *                 because the pointer might change during renegotiation,
+ *                 which happens transparently to the user.
+ *                 If you want to use the certificate across API calls,
+ *                 you must make a copy.
  */
 const mbedtls_x509_crt *mbedtls_ssl_get_peer_cert( const mbedtls_ssl_context *ssl );
 #endif /* MBEDTLS_X509_CRT_PARSE_C */