diff --git a/debian/rules b/debian/rules
index 5c54e27..9c2b184 100755
--- a/debian/rules
+++ b/debian/rules
@@ -43,7 +43,7 @@
 clean-patched:
 	dh_testdir
 	dh_testroot
-	[ -f  config.h.in.backup ] && cp -p config.h.in.backup config.h.in
+	[ ! -f config.h.in.backup ] || cp -p config.h.in.backup config.h.in
 	rm -f build-stamp configure-stamp
 	[ ! -f Makefile ] || $(MAKE) distclean
 	-rm -f `find . -name "*~"`