diff --git a/debian/preinst b/debian/preinst
index 2f214d472..65f04f69c 100755
--- a/debian/preinst
+++ b/debian/preinst
@@ -1,5 +1,5 @@
-#!/bin/sh
-set -e
+#!/bin/bash
+set -eo pipefail; [[ $TRACE ]] && set -x
 
 . /usr/share/debconf/confmodule