diff --git a/Makefile.am b/Makefile.am
index e4c17038..d3230585 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,3 +1,6 @@
+## Process this file with automake to produce Makefile.in -*-Makefile-*-
+AUTOMAKE_OPTIONS = 1.3
+
 #names of parser files
 PFILE = bison.simple
 PFILE1 = bison.hairy