diff --git a/app-shells/rc/rc-1.7.4.ebuild b/app-shells/rc/rc-1.7.4.ebuild
index 551f043253b4a..22f4fd6d06998 100644
--- a/app-shells/rc/rc-1.7.4.ebuild
+++ b/app-shells/rc/rc-1.7.4.ebuild
@@ -35,8 +35,9 @@ src_install() {
 }
 
 pkg_postinst() {
-	ebegin "Updating /etc/shells"
-	( grep -v "^/bin/rcsh$" "${ROOT}"etc/shells; echo "/bin/rcsh" ) > "${T}"/shells
-	mv -f "${T}"/shells "${ROOT}"etc/shells
-	eend $?
+	if ! grep -q '^/bin/rcsh$' "${EROOT}"/etc/shells ; then
+		ebegin "Updating /etc/shells"
+		echo "/bin/rcsh" >> "${EROOT}"/etc/shells
+		eend $?
+	fi
 }