--- Makefile.orig
+++ Makefile
@@ -79,7 +79,7 @@
 	chmod 0755 $(bindir)/roundup
 
 install-man: man
-	-for i in {1..9} ; do cp *.$$i $(mandir)/man$$i 2>/dev/null ; done
+	shopt -s nullglob; for file in *.{1..9}; do install -Dm644 $$file $(mandir)/man$${file##*.}/$${file##*/}; done
 
 .PHONY: pages
 pages : doc