diff --git a/nix/sources.json b/nix/sources.json
index 70693fe..5d10d89 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -23,19 +23,19 @@
         "homepage": "https://mattermost.com",
         "owner": "mattermost",
         "repo": "mattermost-server",
-        "rev": "a5463c865195d0f286de63d57782ef997c270e93",
-        "sha256": "1k0jn3a9nafbhvwn0d0rc2pj80mx7iz2scjbqkz96c5yzw3lyj79",
+        "rev": "868b8d91db6e8a0525a9e93c50a388625d426a4a",
+        "sha256": "1vihpmy7253yl87arlz8y9rahk1q69blykwm3172dk1hxajr7c13",
         "type": "tarball",
-        "url": "https://github.com/mattermost/mattermost-server/archive/refs/tags/v5.37.0.tar.gz",
+        "url": "https://github.com/mattermost/mattermost-server/archive/refs/tags/v5.37.1.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/refs/tags/v<version>.tar.gz",
-        "version": "5.37.0"
+        "version": "5.37.1"
     },
     "mattermost-webapp": {
-        "sha256": "0na9drwnsr5fbrv6qq38dgvd0laj3wjs734ik5s673c0azqlm4kn",
+        "sha256": "00q1kcfda2z69ijpw71a6cbj76p5f57nj7pym44pp4cadi2wz180",
         "type": "tarball",
-        "url": "https://releases.mattermost.com/5.37.0/mattermost-5.37.0-linux-amd64.tar.gz",
+        "url": "https://releases.mattermost.com/5.37.1/mattermost-5.37.1-linux-amd64.tar.gz",
         "url_template": "https://releases.mattermost.com/<version>/mattermost-<version>-linux-amd64.tar.gz",
-        "version": "5.37.0"
+        "version": "5.37.1"
     },
     "mumble-website": {
         "branch": "master",
@@ -81,10 +81,10 @@
         "homepage": "",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "733682c32929293341f113f297b64ea6319e9089",
-        "sha256": "0f6zi45av9s176a2pi15jyf08xk0nsg181hhjhnz3asr0whyarf1",
+        "rev": "2d6ab6c6b92f7aaf8bc53baba9754b9bfdce56f2",
+        "sha256": "1aafqly1mcqxh0r15mrlsrs4znldhm7cizsmfp3d25lqssay6gjd",
         "type": "tarball",
-        "url": "https://github.com/nixos/nixpkgs/archive/733682c32929293341f113f297b64ea6319e9089.tar.gz",
+        "url": "https://github.com/nixos/nixpkgs/archive/2d6ab6c6b92f7aaf8bc53baba9754b9bfdce56f2.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "nixpkgs-unstable": {
@@ -93,10 +93,10 @@
         "homepage": "",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "c464dc811babfe316ed4ab7bbc12351122e69dd7",
-        "sha256": "0aij4q6pc99xjqh0inv6z74wiqfdgxnbg7jli6gnjqxg2lcirrc2",
+        "rev": "fe01052444c1d66ed6ef76df2af798c9769e9e79",
+        "sha256": "0z99hwxgrvlf0psicwd97kdqqcc3qngfzmcz7k68q6q868y8582y",
         "type": "tarball",
-        "url": "https://github.com/nixos/nixpkgs/archive/c464dc811babfe316ed4ab7bbc12351122e69dd7.tar.gz",
+        "url": "https://github.com/nixos/nixpkgs/archive/fe01052444c1d66ed6ef76df2af798c9769e9e79.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "pbb-nixfiles": {
diff --git a/services/mail.nix b/services/mail.nix
index 6c0dfd7..4fe190c 100644
--- a/services/mail.nix
+++ b/services/mail.nix
@@ -30,6 +30,8 @@
         "lenny@hacc.space".hashedPassword = "$6$EZpv9XImv5F3$p2NSoo5gLxh6NnB3/C6wF8knRTuMHqDXYF3BEscaQuk7qok2Z13xKT/6mFvvSKKBnFCuYptgnfGswmoqIzm/1/";
         "lenny@hacc.space".aliases = [ "rinderhacc@hacc.space" ];
 
+        "finance@muc.hacc.space".hashedPassword = "$6$R3GRmvXwqnMM6q.R$Y9mrUAmMnCScsM6pKjxo2a2XPM7lHrV8FIgK0PzhYvZbxWczo7.O4dk1onYeV1mRx/nXZfkZNjqNCruCn0S2m.";
+
         # service accounts
         "noreply@hacc.space".hashedPassword = "$6$YsqMoItITZUzI5wo$5Lejf8XBHRx4LW4VuZ9wJCiBbT4kOV/EZaCdWQ07eVIrkRTZwXWZ5zfsh.olXEFwvpNWN.DBnU.dQc.cC0/ra/";
         "newsletter@hacc.space".hashedPassword = "$6$f0xKnQxBInd$zbVIi1lTKWauqW.c8sMNLHNwzn81oQrVOiIfJwPa98n9xWz/NkjuWLYuFpK.MSZwNwP7Yv/a/qaOb9v8qv/.N1";
diff --git a/services/mattermost.nix b/services/mattermost.nix
index 8a554e7..4045812 100644
--- a/services/mattermost.nix
+++ b/services/mattermost.nix
@@ -1,6 +1,8 @@
 {config, pkgs, lib, profiles, modules, evalConfig, sources, ...}:
 
-{
+let
+  mattermost = pkgs.mattermost;
+in {
   containers.mattermost = {
     autoStart = true;
     privateNetwork = true;
@@ -24,6 +26,8 @@
         ((import sources.nix-hexchen) {}).profiles.nopersist
       ];
 
+      nixpkgs.overlays = [ (self: super: { inherit mattermost; }) ];
+
       nixpkgs.config.allowUnfree = true;
       networking.firewall.enable = false;
       networking.defaultGateway = {
@@ -36,7 +40,7 @@
       services.mattermost-patched = {
         enable = true;
         siteUrl = "https://mattermost.infra4future.de";
-        siteName = "Mattermost - Blabla for Future";
+        siteName = "Mattermost for Future";
         listenAddress = "0.0.0.0:3000";
         mutableConfig = false;
 
@@ -69,6 +73,7 @@
             EnableLaTeX = true;
             ThreadAutoFollow = true;
             EnableSecurityFixAlert = false;
+            CollapsedThreads = "default_on";
           };
           TeamSettings = {
             EnableTeamCreation = true;
@@ -172,8 +177,6 @@
           ClusterSettings.Enable = false;
           MetricsSettings.Enable = false;
           GuestAccountsSettings.Enable = false;
-          # this is just the general allow-this-at-all switch; users
-          # still have to turn it on for themselves
           FeatureFlags.CollapsedThreads = true;
         };