diff --git a/include/mbedtls/ssl_internal.h b/include/mbedtls/ssl_internal.h
index 97c00e2..80da3ac 100644
--- a/include/mbedtls/ssl_internal.h
+++ b/include/mbedtls/ssl_internal.h
@@ -1203,6 +1203,9 @@
 void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl );
 int mbedtls_ssl_resend( mbedtls_ssl_context *ssl );
 int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl );
+#if defined(MBEDTLS_IMMEDIATE_TRANSMISSION)
+void mbedtls_ssl_immediate_flight_done( mbedtls_ssl_context *ssl );
+#endif
 #endif
 
 /* Visible for testing purposes only */