diff --git a/PKGBUILD b/PKGBUILD
index 68e33f0..5069e20 100644
--- a/PKGBUILD
+++ b/PKGBUILD
@@ -71,3 +71,8 @@ package() {
 		install -Dm755 "contrib/$util" -t "$pkgdir/usr/share/$pkgname/scripts"
 	done
 }
+
+post_upgrade() {
+	echo "Make sure to upgrade wlroots-git and sway-git together."
+	echo "Upgrading one but not the other is unsupported."
+}