--- PKGBUILD
+++ PKGBUILD
@@ -15,6 +15,7 @@
 depends=('readline>=7.0' glibc ncurses)
 optdepends=('bash-completion: for tab completion')
 provides=('sh')
+install=bash.install
 source=(https://ftp.gnu.org/gnu/bash/bash-$_basever.tar.gz{,.sig}
         dot.bashrc
         dot.bash_profile
@@ -59,7 +60,6 @@
 
 package() {
   make -C $pkgname-$_basever DESTDIR="$pkgdir" install
-  ln -s bash "$pkgdir/usr/bin/sh"
 
   # system-wide configuration files
   install -Dm644 system.bashrc "$pkgdir/etc/bash.bashrc"
diff -uNr bash.orig/bash.install bash.new/bash.install
--- /dev/null
+++ bash.install
@@ -0,0 +1,3 @@
+post_install() {
+	[ -e /usr/bin/sh ] || ln -s bash /usr/bin/sh
+}