--- PKGBUILD.orig	2016-09-30 17:15:05.968682927 +0200
+++ PKGBUILD	2016-09-30 21:55:56.380786651 +0200
@@ -43,7 +43,7 @@
 
 package() {
   cd $pkgname-v$pkgver
-  make prefix="$pkgdir"/usr install
+  make prefix="$pkgdir"/usr udevdir="$pkgdir"/usr/lib/udev install
 
   # install bash completion (FS#44618)
   install -Dm644 btrfs-completion "$pkgdir/usr/share/bash-completion/completions/btrfs"