diff --git a/Makefile.am b/Makefile.am
index 3e4c6b40..955f25de 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -5,8 +5,8 @@
 # See LICENSE for copying information.
 
 # 'foreign' means that we're not enforcing GNU package rules strictly.
-# '1.7' means that we need automake 1.7 or later (and we do).
-AUTOMAKE_OPTIONS = foreign 1.7 subdir-objects
+# '1.9' means that we need automake 1.9 or later (and we do).
+AUTOMAKE_OPTIONS = foreign 1.9 subdir-objects
 
 ACLOCAL_AMFLAGS = -I m4