diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
new file mode 100644
index 0000000..51c8fe3
--- /dev/null
+++ b/library/ssl_tls13_generic.c
@@ -0,0 +1,67 @@
+/*
+ *  TLS 1.3 functionality shared between client and server
+ *
+ *  Copyright The Mbed TLS Contributors
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include "common.h"
+
+#if defined(MBEDTLS_SSL_TLS_C)
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL)
+
+#include "ssl_misc.h"
+
+int mbedtls_ssl_start_handshake_msg( mbedtls_ssl_context *ssl,
+                                     unsigned hs_type,
+                                     unsigned char **buf,
+                                     size_t *buflen )
+{
+    ((void) ssl);
+    ((void) hs_type);
+    ((void) buf);
+    ((void) buflen);
+    return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+}
+
+int mbedtls_ssl_finish_handshake_msg( mbedtls_ssl_context *ssl,
+                                      size_t buf_len,
+                                      size_t msg_len )
+{
+    ((void) ssl);
+    ((void) buf_len);
+    ((void) msg_len);
+    return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
+}
+
+void mbedtls_ssl_add_hs_hdr_to_checksum( mbedtls_ssl_context *ssl,
+                                         unsigned hs_type,
+                                         size_t total_hs_len )
+{
+    unsigned char hs_hdr[4];
+
+    /* Build HS header for checksum update. */
+    hs_hdr[0] = hs_type;
+    hs_hdr[1] = (unsigned char)( total_hs_len >> 16 );
+    hs_hdr[2] = (unsigned char)( total_hs_len >>  8 );
+    hs_hdr[3] = (unsigned char)( total_hs_len >>  0 );
+
+    ssl->handshake->update_checksum( ssl, hs_hdr, sizeof( hs_hdr ) );
+}
+
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */
+
+#endif /* MBEDTLS_SSL_TLS_C */