diff --git a/matrix-synapse/trunk/PKGBUILD b/matrix-synapse/trunk/PKGBUILD
index ac1c9c56db8..6d2fe3f6efb 100644
--- a/matrix-synapse/trunk/PKGBUILD
+++ b/matrix-synapse/trunk/PKGBUILD
@@ -3,7 +3,7 @@
 
 pkgname=matrix-synapse
 pkgver=1.21.2
-pkgrel=1
+pkgrel=2
 
 pkgdesc="Matrix reference homeserver"
 url="https://github.com/matrix-org/synapse"
@@ -23,18 +23,21 @@ depends=('libwebp' 'python-jsonschema' 'python-twisted' 'python-service-identity
          'python-treq' 'python-idna' 'python-jinja'
          'python-bleach' 'python-typing_extensions' 'systemd')
 checkdepends=('python-authlib' 'python-pyjwt' 'python-lxml' 'python-mock' 'python-parameterized')
+makedepends=('git')
 optdepends=('perl: sync_room_to_group.pl'
             'python-psycopg2: PostgreSQL support'
             'python-lxml: URL previewing'
             'python-psutil: metrics'
             'python-pyjwt: jwt')
 
-source=("synapse-$pkgver.tar.gz::https://github.com/matrix-org/synapse/archive/v$pkgver.tar.gz"
+source=("git+https://github.com/matrix-org/synapse.git#tag=v${pkgver}?signed"
         'synapse.service'
         'sysusers-synapse.conf'
         'tmpfiles-synapse.conf')
 
-md5sums=('f7a3a347bdf5c0844dcf7f77f3baa246'
+validpgpkeys=('177B595E4DFCB510C556750833FC58F6A7113048') # Patrick Cloke <patrickc@matrix.org>
+
+md5sums=('SKIP'
          'fb196dee4f38a4b19e0a160f45574032'
          'ecd9f66fb57fe1a2e1e2df07a460a35b'
          'e961c9ecad84a70345a57a7e9e6d5b09')
@@ -43,19 +46,19 @@ backup=('etc/synapse/log_config.yaml')
 install=synapse.install
 
 build() {
-	cd synapse-$pkgver
+	cd synapse
 	python setup.py build
 }
 
 check() {
-	cd synapse-$pkgver
+	cd synapse
 	PYTHONPATH=. trial3 tests
 }
 
 package() {
 	install -Dm644 synapse.service "$pkgdir"/usr/lib/systemd/system/synapse.service
 
-	cd synapse-$pkgver
+	cd synapse
 	python setup.py install --root "$pkgdir" --optimize=1 --skip-build
 
 	install -dm755 -o 198 -g 198 "$pkgdir"/etc/synapse