diff --git a/flake.lock b/flake.lock
index 9e069cb..87b39bd 100644
--- a/flake.lock
+++ b/flake.lock
@@ -79,11 +79,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1764072303,
-        "narHash": "sha256-R8WxY9F5HNSZstrlsTqxbDMpq7qHzO6TW1uUew849dQ=",
+        "lastModified": 1764374374,
+        "narHash": "sha256-naS7hg/D1yLKSZoENx9gvsPLFiNEOTcqamJSu0OEvCA=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "798ce8bfd0567bbd12ee633a88e53737969ec7d9",
+        "rev": "6a49303095abc094ee77dc243a9e351b642e8e75",
         "type": "github"
       },
       "original": {
diff --git a/mail-server/assertions.nix b/mail-server/assertions.nix
index 374c17b..1885af4 100644
--- a/mail-server/assertions.nix
+++ b/mail-server/assertions.nix
@@ -5,7 +5,7 @@
 }:
 
 let
-  mailserverRelease = "25.11";
+  mailserverRelease = "26.05";
   nixpkgsRelease = lib.trivial.release;
   releaseMismatch =
     config.mailserver.enableNixpkgsReleaseCheck && mailserverRelease != nixpkgsRelease;