diff --git a/CONTROL/preinst b/CONTROL/preinst
index f2f4590..46a1a21 100755
--- a/CONTROL/preinst
+++ b/CONTROL/preinst
@@ -1,7 +1,12 @@
 #!/bin/sh
 
 f=/mod/etc/sweeper.conf
-[ -f $f ] && cp $f $f~
+if [ -f $f ]; then
+	sum=`/mod/bin/busybox/md5sum $f | awk '{print $1}'`
+	if [ "$sum" != "a22cb1379fb9c58ae549dead9695eebe" ]; then
+		cp $f $f~
+	fi
+fi
 
 exit 0