diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 69d9c66..1516523 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1328,6 +1328,7 @@
 
     handshake->transform_handshake = transform_handshake;
     mbedtls_ssl_set_inbound_transform( ssl, transform_handshake );
+    mbedtls_ssl_set_outbound_transform( ssl, ssl->handshake->transform_handshake );
 
     MBEDTLS_SSL_DEBUG_MSG( 1, ( "Switch to handshake keys for inbound traffic" ) );
     ssl->session_in = ssl->session_negotiate;