diff --git a/debian/changelog b/debian/changelog
index 4d5c627..8f3daf2 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,5 +1,6 @@
 nut (2.6.5-3) UNRELEASED; urgency=low
 
+  [ Laurent Bigonville ]
   * debian/control:
     - Move libupsclient1 package to libs Section
     - Add libgd-dev to the Build-Depends, keep the other alternatives to ease
@@ -9,6 +10,11 @@ nut (2.6.5-3) UNRELEASED; urgency=low
       getting updated during build
     - Use canonical URL for the VCS-* fields
 
+  [ Ivo De Decker ]
+  * debian/nut-client.preinst: also revert /etc/nut/nut.conf mangling done
+    by postinst during upgrade from lenny to squeeze (Really closes: #677054)
+    Thanks to Andreas Beckmann for the review.
+
  -- Laurent Bigonville <bigon@debian.org>  Tue, 14 May 2013 18:04:04 +0200
 
 nut (2.6.5-2) experimental; urgency=low
diff --git a/debian/nut-client.preinst b/debian/nut-client.preinst
index 2107da1..fa1bd01 100644
--- a/debian/nut-client.preinst
+++ b/debian/nut-client.preinst
@@ -4,6 +4,15 @@ set -e
 
 # Revert /etc/nut/nut.conf mangling done by older versions of the postinst
 # See #677054
+# changed configfile created by a fresh install in lenny, upgraded to squeeze
+if [ "$1" = "install" -o "$1" = "upgrade" ] \
+    && dpkg --compare-versions "$2" lt "2.6.4-2" \
+    && [ -f /etc/nut/nut.conf ] \
+    && [ "`md5sum /etc/nut/nut.conf | cut -d ' ' -f 1`" = 331cca39153f451c2968f4b734c1cf3f ]; then
+       sed -i '29,$ d' /etc/nut/nut.conf
+fi
+
+# changed configfile created by a fresh install in squeeze
 if [ "$1" = "install" -o "$1" = "upgrade" ] \
     && dpkg --compare-versions "$2" lt "2.6.4-2" \
     && [ -f /etc/nut/nut.conf ] \