diff --git a/include/libwebsockets/lws-system.h b/include/libwebsockets/lws-system.h
index 789724c7a..9578df455 100644
--- a/include/libwebsockets/lws-system.h
+++ b/include/libwebsockets/lws-system.h
@@ -35,6 +35,7 @@ typedef enum {
 	LWS_SYSI_HRS_DEVICE_SERIAL,
 	LWS_SYSI_HRS_FIRMWARE_VERSION,
 	LWS_SYSI_HRS_NTP_SERVER,
+	LWS_SYSI_HRS_CLIENT_CERT_DER,
 
 	LWS_SYSI_USER_BASE = 100
 } lws_system_item_t;