diff --git a/srcpkgs/rcs/template b/srcpkgs/rcs/template
index cc7da20c7cc..0a5e5c41334 100644
--- a/srcpkgs/rcs/template
+++ b/srcpkgs/rcs/template
@@ -1,7 +1,7 @@
 # Template file for 'rcs'
 pkgname=rcs
 version=5.9.4
-revision=2
+revision=3
 build_style=gnu-configure
 hostmakedepends="ed groff"
 makedepends="ed"
@@ -12,3 +12,4 @@ license="GPL-3"
 homepage="http://www.gnu.org/software/rcs/"
 distfiles="${GNU_SITE}/${pkgname}/${pkgname}-${version}.tar.xz"
 checksum=063d5a0d7da1821754b80c639cdae2c82b535c8ff4131f75dc7bbf0cd63a5dff
+CFLAGS="-std=c99"