--- a/debian/postrm	Mon Nov 09 21:54:27 2015 +0100
+++ b/debian/postrm	Mon Nov 09 22:25:53 2015 +0100
@@ -19,22 +19,24 @@
 # the debian-policy package
 
 CONF=/etc/ca-certificates.conf
-CRT="schlittermann-ca*.crt"
+CRT="schlittermann-ca.*\.crt"
 
 case "$1" in
     purge)
 	TMP=`mktemp`
-	grep -v "$CRT" <$CONF >$TMP
+	grep -v "$CRT" $CONF >$TMP
 	cp $TMP $CONF
 	rm $TMP
 	update-ca-certificates --fresh
     ;;
 
     remove|upgrade|failed-upgrade|abort-install|abort-upgrade|disappear)
-	tmp=`mktemp`
-	grep -F -v 'schlittermann-ca.crt' $CONF
-	cp $tmp $CONF
-	rm $tmp
+	if test -s "$CONF"; then
+	    tmp=`mktemp`
+	    grep -F -v 'schlittermann-ca.crt' $CONF >$tmp
+	    cp $tmp $CONF
+	    rm $tmp
+	fi
 	update-ca-certificates --fresh
     ;;