diff --git a/nixos/modules/services/finance/taler/common.nix b/nixos/modules/services/finance/taler/common.nix
index c6ade43084fd..891562c90ff8 100644
--- a/nixos/modules/services/finance/taler/common.nix
+++ b/nixos/modules/services/finance/taler/common.nix
@@ -51,7 +51,7 @@ in
       (lib.genAttrs (map (n: "taler-${talerComponent}-${n}") services) (name: {
         serviceConfig = {
           DynamicUser = true;
-          User = name;
+          User = dbName;
           Group = groupName;
           ExecStart = toString [
             (lib.getExe' cfg.package name)
@@ -85,6 +85,7 @@ in
             Type = "oneshot";
             DynamicUser = true;
             User = dbName;
+            Group = groupName;
             Restart = "on-failure";
             RestartSec = "5s";
           };
@@ -116,7 +117,7 @@ in
     services.postgresql = {
       enable = true;
       ensureDatabases = [ dbName ];
-      ensureUsers = map (service: { name = "taler-${talerComponent}-${service}"; }) servicesDB ++ [
+      ensureUsers = [
         {
           name = dbName;
           ensureDBOwnership = true;
diff --git a/nixos/modules/services/finance/taler/exchange.nix b/nixos/modules/services/finance/taler/exchange.nix
index 4a940cddb104..2b5861608a09 100644
--- a/nixos/modules/services/finance/taler/exchange.nix
+++ b/nixos/modules/services/finance/taler/exchange.nix
@@ -133,24 +133,8 @@ in
       after = [ "taler-exchange-httpd.service" ];
     };
 
-    # Taken from https://docs.taler.net/taler-exchange-manual.html#exchange-database-setup
-    # TODO: Why does aggregator need DELETE?
-    systemd.services."taler-${talerComponent}-dbinit".script =
-      let
-        deletePerm = name: lib.optionalString (name == "aggregator") ",DELETE";
-        dbScript = pkgs.writers.writeText "taler-exchange-db-permissions.sql" (
-          lib.pipe servicesDB [
-            (map (name: ''
-              GRANT SELECT,INSERT,UPDATE${deletePerm name} ON ALL TABLES IN SCHEMA exchange TO "taler-exchange-${name}";
-              GRANT USAGE ON ALL SEQUENCES IN SCHEMA exchange TO "taler-exchange-${name}";
-            ''))
-            lib.concatStrings
-          ]
-        );
-      in
-      ''
-        ${lib.getExe' cfg.package "taler-exchange-dbinit"} -c ${configFile}
-        psql -U taler-exchange-httpd -f ${dbScript}
-      '';
+    systemd.services."taler-${talerComponent}-dbinit".script = ''
+      ${lib.getExe' cfg.package "taler-exchange-dbinit"} -c ${configFile}
+    '';
   };
 }
diff --git a/nixos/modules/services/finance/taler/merchant.nix b/nixos/modules/services/finance/taler/merchant.nix
index 1426882ac050..a541ba2d5b25 100644
--- a/nixos/modules/services/finance/taler/merchant.nix
+++ b/nixos/modules/services/finance/taler/merchant.nix
@@ -90,21 +90,8 @@ in
       path = [ cfg.package ];
     };
 
-    systemd.services."taler-${talerComponent}-dbinit".script =
-      let
-        # NOTE: not documented, but is necessary
-        dbScript = pkgs.writers.writeText "taler-merchant-db-permissions.sql" (
-          lib.concatStrings (
-            map (name: ''
-              GRANT SELECT,INSERT,UPDATE,DELETE ON ALL TABLES IN SCHEMA merchant TO "taler-merchant-${name}";
-              GRANT USAGE ON ALL SEQUENCES IN SCHEMA merchant TO "taler-merchant-${name}";
-            '') servicesDB
-          )
-        );
-      in
-      ''
-        ${lib.getExe' cfg.package "taler-merchant-dbinit"} -c ${configFile}
-        psql -U taler-${talerComponent}-httpd -f ${dbScript}
-      '';
+    systemd.services."taler-${talerComponent}-dbinit".script = ''
+      ${lib.getExe' cfg.package "taler-merchant-dbinit"} -c ${configFile}
+    '';
   };
 }