diff --git a/addons/web/static/src/core/user_service.js b/addons/web/static/src/core/user_service.js
index 5feade2beac..4e040d4504a 100644
--- a/addons/web/static/src/core/user_service.js
+++ b/addons/web/static/src/core/user_service.js
@@ -57,7 +57,7 @@ export const userService = {
                 return settings;
             },
             async setUserSettings(key, value) {
-                settings = await env.services.orm.call(
+                const changedSettings = await env.services.orm.call(
                     "res.users.settings",
                     "set_res_users_settings",
                     [[this.settings.id]],
@@ -67,6 +67,7 @@ export const userService = {
                         },
                     }
                 );
+                Object.assign(settings, changedSettings);
             },
             name: session.name,
             userName: session.username,
diff --git a/addons/web/static/tests/core/user_service_tests.js b/addons/web/static/tests/core/user_service_tests.js
index 02a5728663b..72fbbb29d36 100644
--- a/addons/web/static/tests/core/user_service_tests.js
+++ b/addons/web/static/tests/core/user_service_tests.js
@@ -3,6 +3,8 @@
 import { registry } from "@web/core/registry";
 import { userService } from "@web/core/user_service";
 import { makeTestEnv } from "../helpers/mock_env";
+import { session } from "@web/session";
+import { patchWithCleanup } from "@web/../tests/helpers/utils";
 
 const serviceRegistry = registry.category("services");
 
@@ -25,3 +27,22 @@ QUnit.test("successive calls to hasGroup", async (assert) => {
 
     assert.verifySteps(["res.users/has_group/x", "res.users/has_group/y"]);
 });
+
+QUnit.test("set user settings do not override old valid keys", async (assert) => {
+    patchWithCleanup(session, {
+        ...session,
+        user_settings: { a: 1, b: 2 },
+    });
+    serviceRegistry.add("user", userService);
+
+    const mockRPC = (route, args) => {
+        assert.step(JSON.stringify(args.kwargs.new_settings));
+        return { a: 3, c: 4 };
+    };
+    const env = await makeTestEnv({ mockRPC });
+    assert.deepEqual(env.services.user.settings, { a: 1, b: 2 });
+
+    await env.services.user.setUserSettings("a", 3);
+    assert.verifySteps(['{"a":3}']);
+    assert.deepEqual(env.services.user.settings, { a: 3, b: 2, c: 4 });
+});