diff --git a/sys-devel/autoconf/autoconf-2.71.recipe b/sys-devel/autoconf/autoconf-2.71.recipe
index e3c672b43..fddc93a1e 100644
--- a/sys-devel/autoconf/autoconf-2.71.recipe
+++ b/sys-devel/autoconf/autoconf-2.71.recipe
@@ -7,7 +7,7 @@ HOMEPAGE="http://www.gnu.org/software/autoconf/"
 COPYRIGHT="1996, 2000-2001, 2005, 2007-2017, 2020-2021 Free Software"
 LICENSE="GNU GPL v2
 	GNU GPL v3"
-REVISION="1"
+REVISION="2"
 SOURCE_URI="http://ftp.gnu.org/gnu/autoconf/autoconf-2.71.tar.gz"
 CHECKSUM_SHA256="431075ad0bf529ef13cb41e9042c542381103e80015686222b8a9d4abef42a1c"
 BUILD_PACKAGE_ACTIVATION_PHASE="INSTALL"
@@ -44,6 +44,7 @@ BUILD_PREREQUIRES="
 	cmd:makeinfo
 	cmd:perl >= 5
 	cmd:sed
+	cmd:cmp
 	"
 
 BUILD()