diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 296b628..86220d2 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1677,6 +1677,12 @@
 int mbedtls_ssl_tls13_process_certificate_verify( mbedtls_ssl_context *ssl );
 
 /*
+ * Write of dummy-CCS's for middlebox compatibility
+ */
+int mbedtls_ssl_tls13_write_change_cipher_spec( mbedtls_ssl_context *ssl );
+
+
+/*
  * Write TLS 1.3 handshake message tail
  */
 int mbedtls_ssl_tls13_finish_handshake_msg( mbedtls_ssl_context *ssl,