diff --git a/library/ssl_tls13_keys.h b/library/ssl_tls13_keys.h
index 941a19e..693b6c4 100644
--- a/library/ssl_tls13_keys.h
+++ b/library/ssl_tls13_keys.h
@@ -662,6 +662,17 @@
  */
 int mbedtls_ssl_tls13_compute_handshake_transform( mbedtls_ssl_context *ssl );
 
+/**
+ * \brief Compute TLS 1.3 application transform
+ *
+ * \param ssl  The SSL context to operate on. The early secret must have been
+ *             computed.
+ *
+ * \returns    \c 0 on success.
+ * \returns    A negative error code on failure.
+ */
+int mbedtls_ssl_tls13_compute_application_transform( mbedtls_ssl_context *ssl );
+
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
 
 #endif /* MBEDTLS_SSL_TLS1_3_KEYS_H */