diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index 3ca28d5..6dc27a4 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -593,6 +593,56 @@
     return( 0 );
 }
 
+#if defined(MBEDTLS_SSL_NEW_SESSION_TICKET)
+int mbedtls_ssl_tls1_3_generate_resumption_master_secret(
+    mbedtls_ssl_context *ssl )
+{
+    int ret = 0;
+
+    mbedtls_md_type_t md_type;
+    mbedtls_md_info_t const *md_info;
+    size_t md_size;
+
+    unsigned char transcript[MBEDTLS_MD_MAX_SIZE];
+    size_t transcript_len;
+
+    MBEDTLS_SSL_DEBUG_MSG( 2,
+          ( "=> mbedtls_ssl_tls1_3_generate_resumption_master_secret" ) );
+
+    md_type = ssl->handshake->ciphersuite_info->mac;
+    md_info = mbedtls_md_info_from_type( md_type );
+    md_size = mbedtls_md_get_size( md_info );
+
+    ret = mbedtls_ssl_get_handshake_transcript( ssl, md_type,
+                                                transcript, sizeof( transcript ),
+                                                &transcript_len );
+    if( ret != 0 )
+        return( ret );
+
+    ret = mbedtls_ssl_tls1_3_derive_resumption_master_secret( md_type,
+                              ssl->handshake->tls1_3_master_secrets.app,
+                              transcript, transcript_len,
+                              &ssl->session_negotiate->app_secrets );
+    if( ret != 0 )
+        return( ret );
+
+    MBEDTLS_SSL_DEBUG_BUF( 4, "Resumption master secret",
+             ssl->session_negotiate->app_secrets.resumption_master_secret,
+             md_size );
+
+    MBEDTLS_SSL_DEBUG_MSG( 2,
+          ( "<= mbedtls_ssl_tls1_3_generate_resumption_master_secret" ) );
+    return( 0 );
+}
+#else /* MBEDTLS_SSL_NEW_SESSION_TICKET */
+int mbedtls_ssl_tls1_3_generate_resumption_master_secret(
+    mbedtls_ssl_context *ssl )
+{
+    ((void) ssl);
+    return( 0 );
+}
+#endif /* MBEDTLS_SSL_NEW_SESSION_TICKET */
+
 static int ssl_tls1_3_calc_finished_core( mbedtls_md_type_t md_type,
                                           unsigned char const *base_key,
                                           unsigned char const *transcript,