diff --git a/nixos/modules/services/web-apps/mediawiki.nix b/nixos/modules/services/web-apps/mediawiki.nix
index e9ed53857d81..0a5b6047bb58 100644
--- a/nixos/modules/services/web-apps/mediawiki.nix
+++ b/nixos/modules/services/web-apps/mediawiki.nix
@@ -29,7 +29,7 @@ let
       '') cfg.skins)}
 
       ${concatStringsSep "\n" (mapAttrsToList (k: v: ''
-        ln -s ${v} $out/share/mediawiki/extensions/${k}
+        ln -s ${if v != null then v else "$src/share/mediawiki/extensions/${k}"} $out/share/mediawiki/extensions/${k}
       '') cfg.extensions)}
     '';
   };
@@ -204,17 +204,28 @@ in
         default = {};
         type = types.attrsOf types.path;
         description = ''
-          List of paths whose content is copied to the 'skins'
-          subdirectory of the MediaWiki installation.
+          Attribute set of paths whose content is copied to the <filename>skins</filename>
+          subdirectory of the MediaWiki installation in addition to the default skins.
         '';
       };
 
       extensions = mkOption {
         default = {};
-        type = types.attrsOf types.path;
+        type = types.attrsOf (types.nullOr types.path);
         description = ''
-          List of paths whose content is copied to the 'extensions'
-          subdirectory of the MediaWiki installation.
+          Attribute set of paths whose content is copied to the <filename>extensions</filename>
+          subdirectory of the MediaWiki installation and enabled in configuration.
+
+          Use <literal>null</literal> instead of path to enable extensions that are part of MediaWiki.
+        '';
+        example = literalExample ''
+          {
+            Matomo = pkgs.fetchzip {
+              url = "https://github.com/DaSchTour/matomo-mediawiki-extension/archive/v4.0.1.tar.gz";
+              sha256 = "0g5rd3zp0avwlmqagc59cg9bbkn3r7wx7p6yr80s644mj6dlvs1b";
+            };
+            ParserFunctions = null;
+          }
         '';
       };
 
diff --git a/nixos/tests/mediawiki.nix b/nixos/tests/mediawiki.nix
index 9468c1de8ccb..008682310cf6 100644
--- a/nixos/tests/mediawiki.nix
+++ b/nixos/tests/mediawiki.nix
@@ -8,6 +8,13 @@ import ./make-test-python.nix ({ pkgs, lib, ... }: {
       services.mediawiki.virtualHost.hostName = "localhost";
       services.mediawiki.virtualHost.adminAddr = "root@example.com";
       services.mediawiki.passwordFile = pkgs.writeText "password" "correcthorsebatterystaple";
+      services.mediawiki.extensions = {
+        Matomo = pkgs.fetchzip {
+          url = "https://github.com/DaSchTour/matomo-mediawiki-extension/archive/v4.0.1.tar.gz";
+          sha256 = "0g5rd3zp0avwlmqagc59cg9bbkn3r7wx7p6yr80s644mj6dlvs1b";
+        };
+        ParserFunctions = null;
+      };
     };
 
   testScript = ''