diff --git a/Doc/paper-letter/Makefile b/Doc/paper-letter/Makefile
index e193bc9..6935006 100644
--- a/Doc/paper-letter/Makefile
+++ b/Doc/paper-letter/Makefile
@@ -138,3 +138,6 @@
 
 clobber: clean
 	rm -f $(DVIFILES) $(PSFILES) $(PDFFILES)
+
+realclean: clobber
+distclean: clobber