diff --git a/debian/prometheus-entrouvert-exporter.postinst b/debian/prometheus-entrouvert-exporter.postinst
new file mode 100644
index 0000000..59815b0
--- /dev/null
+++ b/debian/prometheus-entrouvert-exporter.postinst
@@ -0,0 +1,22 @@
+#! /bin/sh
+
+set -e
+
+case "$1" in
+  configure)
+    # remove obsolete timer
+    test -e /etc/systemd/system/timers.target.wants/prometheus-entrouvert-exporter.timer && systemctl disable prometheus-entrouvert-exporter.timer
+  ;;
+
+  abort-upgrade|abort-remove|abort-deconfigure|triggered)
+  ;;
+
+  *)
+    echo "postinst called with unknown argument \`$1'" >&2
+    exit 1
+  ;;
+esac
+
+#DEBHELPER#
+
+exit 0