diff --git a/nixos/base/nixpkgs.nix b/nixos/base/nixpkgs.nix
index 6404e809..c99eb47e 100644
--- a/nixos/base/nixpkgs.nix
+++ b/nixos/base/nixpkgs.nix
@@ -5,6 +5,7 @@ in {
     overlays = [
       inputs.arcexprs.overlays.default
       overlays.default
+      overlays.unifi
     ];
     config = {
       allowUnfree = true;
diff --git a/overlays/default.nix b/overlays/default.nix
index 116b888d..1c1d278c 100644
--- a/overlays/default.nix
+++ b/overlays/default.nix
@@ -16,6 +16,7 @@ in rec {
   nfs = import ./nfs.nix;
   nginx = import ./nginx.nix;
   samba = import ./samba.nix;
+  unifi = import ./unifi.nix;
   deploy-rs = inputs.deploy-rs.overlays.default or inputs.deploy-rs.overlay;
   arc = inputs.arcexprs.overlays.default;
 }
diff --git a/overlays/unifi.nix b/overlays/unifi.nix
new file mode 100644
index 00000000..a020eda0
--- /dev/null
+++ b/overlays/unifi.nix
@@ -0,0 +1,14 @@
+final: prev: let
+  inherit (final) lib;
+in {
+  mongodb-5_0 = let
+    mongodb-5_0_26 = prev.mongodb-5_0.overrideAttrs (old: rec {
+      version = "5.0.26";
+      name = "${old.pname}-${version}";
+      src = final.fetchurl {
+        url = "https://fastdl.mongodb.org/src/mongodb-src-r${version}.tar.gz";
+        sha256 = "sha256-GGvE52zCu2tg4p35XJ5I78nBxRUp4KwBqlmtiv50N7w=";
+      };
+    });
+  in lib.warnIf (lib.versionAtLeast prev.mongodb-5_0.version "5.0.26") "mongodb 5.0 updated in upstream nixpkgs, overlay no longer needed" mongodb-5_0_26;
+}