diff --git a/.gitmodules b/.gitmodules
index c03e3cb..427c957 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -4,3 +4,6 @@
 [submodule "server"]
 	path = server
 	url = https://github.com/nextcloud/server.git
+[submodule "dav"]
+	path = dav
+	url = https://github.com/sabre-io/dav.git
diff --git a/Makefile b/Makefile
index 050d53d..4b53abb 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-all:
+build:
 	git submodule update --init
 	# Build server
 	cd server && git submodule update --init
@@ -11,6 +11,5 @@ all:
 clean:
 	rm nixos.qcow2
 
-
 run:
 	QEMU_NET_OPTS="hostfwd=tcp::8080-:80,hostfwd=tcp::1433-:143,hostfwd=tcp::5877-:587" nixos-shell vm-nextcloud.nix
diff --git a/dav b/dav
new file mode 160000
index 0000000..1ddd773
--- /dev/null
+++ b/dav
@@ -0,0 +1 @@
+Subproject commit 1ddd7733a3dbec1880f695e979e9272dfb0795aa
diff --git a/vm-nextcloud.nix b/vm-nextcloud.nix
index 4108bc1..487bda3 100644
--- a/vm-nextcloud.nix
+++ b/vm-nextcloud.nix
@@ -52,13 +52,17 @@
   };
   # Mount our local development repositories into the VM
   nixos-shell.mounts.extraMounts = {
+    "/var/lib/nextcloud/server" = {
+      target = ./server;
+      cache = "none";
+    };
     "/var/lib/nextcloud/store-apps/calendar" = {
        target = ./calendar;
        cache = "none";
     };
-    "/var/lib/nextcloud/server" = {
-      target = ./server;
-      cache = "none";
+    "/var/lib/nextcloud/server/3rdparty/sabre/dav" = {
+       target = ./dav;
+       cache = "none";
     };
   };
   services.nginx.virtualHosts."localhost".root = lib.mkForce "/var/lib/nextcloud/server";