diff --git a/nixos/tests/postgresql/postgresql.nix b/nixos/tests/postgresql/postgresql.nix
index 509a14411de9c..803c16e7819f3 100644
--- a/nixos/tests/postgresql/postgresql.nix
+++ b/nixos/tests/postgresql/postgresql.nix
@@ -26,6 +26,15 @@ let
     INSERT INTO sth (id) VALUES (1);
     CREATE TABLE xmltest ( doc xml );
     INSERT INTO xmltest (doc) VALUES ('<test>ok</test>'); -- check if libxml2 enabled
+    -- check if hardening gets relaxed
+    CREATE EXTENSION plv8;
+    DO $$
+      let xs = [];
+      for (let i = 0, n = 4000000000; i < n; i++) {
+          xs.push(Math.round(Math.random() * n))
+      }
+      console.log(Math.sum(xs));
+    $$ LANGUAGE plv8;
   '';
 
   makeTestForWithBackupAll =
@@ -42,6 +51,7 @@ let
           services.postgresql = {
             inherit (package) ;
             enable = true;
+            extraPlugins = ps: with ps; [ plv8 ];
           };
 
           services.postgresqlBackup = {