diff -up tree-1.5.1.1/Makefile.preserve-timestamps tree-1.5.1.1/Makefile
--- tree-1.5.1.1/Makefile.preserve-timestamps	2008-04-25 12:30:41.000000000 +0100
+++ tree-1.5.1.1/Makefile	2008-04-25 12:31:14.000000000 +0100
@@ -62,9 +62,9 @@ install:
 	install -d $(BINDIR)
 	install -d $(MANDIR)
 	if [ -e $(TREE_DEST) ]; then \
-		install $(TREE_DEST) $(BINDIR)/$(TREE_DEST); \
+		install -p $(TREE_DEST) $(BINDIR)/$(TREE_DEST); \
 	fi
-	install man/$(MAN) $(MANDIR)/$(MAN)
+	install -p man/$(MAN) $(MANDIR)/$(MAN)
 
 distclean:
 	if [ -f tree.o ]; then rm *.o; fi