diff --git a/frr/MESSAGE b/frr/MESSAGE
index 2e9e8bb487..382dfbff84 100644
--- a/frr/MESSAGE
+++ b/frr/MESSAGE
@@ -1,6 +1,10 @@
 ===========================================================================
 $NetBSD: MESSAGE,v 1.1 2020/07/28 06:36:29 kardel Exp $
 
+IMPORTANT:
+To complete the installation you need to add
+the user "${FRR_USER}" to the (secondary) group "${FRR_VTY_GROUP}".
+
 You can find some example config files in
 ${PREFIX}/share/examples/frr
 
diff --git a/frr/Makefile b/frr/Makefile
index d74bfc71ab..16fc6de85f 100644
--- a/frr/Makefile
+++ b/frr/Makefile
@@ -54,6 +54,9 @@ REPLACE_BASH=	tools/frr.in tools/*.sh.in
 
 REPLACE_PYTHON=	tools/generate_support_bundle.py tools/frr-reload.py
 
+MESSAGE_SUBST+=		FRR_USER=${FRR_USER}
+MESSAGE_SUBST+=		FRR_VTY_GROUP=${FRR_VTY_GROUP}
+
 SUBST_CLASSES+=		ids
 SUBST_STAGE.ids=	pre-configure
 SUBST_MESSAGE.ids=	Fixing user/group references.