diff --git a/addons/web/static/src/core/orm_service.js b/addons/web/static/src/core/orm_service.js
index f0703180f1f..c5f43cd1fe9 100644
--- a/addons/web/static/src/core/orm_service.js
+++ b/addons/web/static/src/core/orm_service.js
@@ -189,6 +189,7 @@ export class ORM {
         validateArray("domain", domain);
         validatePrimitiveList("fields", "string", fields);
         validatePrimitiveList("groupby", "string", groupby);
+        groupby = [...new Set(groupby)];
         return this.call(model, "read_group", [], { ...kwargs, domain, fields, groupby });
     }
 
diff --git a/addons/web/static/tests/core/orm_service_tests.js b/addons/web/static/tests/core/orm_service_tests.js
index c6ba0299bd6..2e2fc0f3b2e 100644
--- a/addons/web/static/tests/core/orm_service_tests.js
+++ b/addons/web/static/tests/core/orm_service_tests.js
@@ -297,6 +297,23 @@ QUnit.test("readGroup method", async (assert) => {
     });
 });
 
+QUnit.test("test readGroup method removes duplicate values from groupby", async (assert) => {
+    const [query, rpc] = makeFakeRPC();
+    serviceRegistry.add("rpc", rpc);
+    const env = await makeTestEnv();
+    await env.services.orm.readGroup(
+        "sale.order",
+        [["user_id", "=", 2]],
+        ["amount_total:sum"],
+        ["date_order:month", "date_order:month"],
+        { offset: 1 }
+    );
+    assert.strictEqual(query.route, "/web/dataset/call_kw/sale.order/read_group");
+    assert.deepEqual(query.params.kwargs.groupby, ["date_order:month"],
+        "Duplicate values should be removed from groupby"
+    );
+});
+
 QUnit.test("searchRead method", async (assert) => {
     const [query, rpc] = makeFakeRPC();
     serviceRegistry.add("rpc", rpc);