diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 71987e0..68971cd 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1735,6 +1735,7 @@
  */
 int mbedtls_ssl_tls13_process_certificate( mbedtls_ssl_context *ssl );
 
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
 /*
  * Handler of TLS 1.3 write certificate message
  */
@@ -1744,6 +1745,9 @@
  * Handler of TLS 1.3 write certificate verify message
  */
 int mbedtls_ssl_tls13_write_certificate_verify( mbedtls_ssl_context *ssl );
+
+#endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
+
 /*
  * Generic handler of Certificate Verify
  */