diff --git a/debian/pve-kernel-helper.install b/debian/pve-kernel-helper.install
index aae9494..f03b05a 100644
--- a/debian/pve-kernel-helper.install
+++ b/debian/pve-kernel-helper.install
@@ -1,3 +1,4 @@
+etc/grub.d/000_proxmox_boot_header
 etc/kernel/postinst.d/*
 etc/kernel/postrm.d/*
 etc/initramfs/post-update.d/proxmox-boot-sync
diff --git a/proxmox-boot/000_proxmox_boot_header b/proxmox-boot/000_proxmox_boot_header
new file mode 100755
index 0000000..e230aef
--- /dev/null
+++ b/proxmox-boot/000_proxmox_boot_header
@@ -0,0 +1,22 @@
+#! /bin/sh
+set -e
+
+. /usr/share/pve-kernel-helper/scripts/functions
+
+if proxmox-boot-tool status --quiet; then
+	cat <<- EOF
+	#
+	# This system is booted via proxmox-boot-tool! The grub-config used when
+	# booting from the disks configured with proxmox-boot-tool resides on the vfat
+	# partitions with UUIDs listed in ${ESP_LIST}.
+	# /boot/grub/grub.cfg is NOT read when booting from those disk!
+	EOF
+
+	if [ -z "$DPKG_RUNNING_VERSION" ] && [ -z "$PVE_EFIBOOT_UNSHARED" ]; then
+		warn "W: This system is booted via proxmox-boot-tool:"
+		warn "W: Running update-grub does not update the correct config!"
+		warn "W: Run 'proxmox-boot-tool refresh' instead."
+		warn ""
+	fi
+fi
+
diff --git a/proxmox-boot/Makefile b/proxmox-boot/Makefile
index 3a36cb7..effd726 100644
--- a/proxmox-boot/Makefile
+++ b/proxmox-boot/Makefile
@@ -1,11 +1,13 @@
 KERNEL_HOOKSCRIPTS = proxmox-auto-removal zz-proxmox-boot
 INITRAMFS_HOOKSCRIPTS = proxmox-boot-sync
 SHARE_FILES = functions
+GRUB_CFG_SNIPPET = 000_proxmox_boot_header
 
 POSTINSTHOOKDIR = ${DESTDIR}/etc/kernel/postinst.d
 POSTRMHOOKDIR = ${DESTDIR}/etc/kernel/postrm.d
 POSTINITRAMFSHOOKDIR = ${DESTDIR}/etc/initramfs/post-update.d
 SHARE_SCRIPTDIR = ${DESTDIR}/usr/share/pve-kernel-helper/scripts
+GRUB_CFG_DIR = ${DESTDIR}/etc/grub.d
 
 .PHONY: all
 all:
@@ -19,6 +21,8 @@ install:
 	install -m 0755 ${INITRAMFS_HOOKSCRIPTS} ${POSTINITRAMFSHOOKDIR}
 	install -d ${SHARE_SCRIPTDIR}
 	install -m 0755 ${SHARE_FILES} ${SHARE_SCRIPTDIR}
+	install -d ${GRUB_CFG_DIR}
+	install -m 0755 ${GRUB_CFG_SNIPPET} ${GRUB_CFG_DIR}
 
 .PHONY: clean distclean
 distclean: