diff --git a/addons/mail/static/src/core/web/chatter.js b/addons/mail/static/src/core/web/chatter.js
index 903ff7b68f9..a5b04544195 100644
--- a/addons/mail/static/src/core/web/chatter.js
+++ b/addons/mail/static/src/core/web/chatter.js
@@ -26,6 +26,7 @@ import {
     useState,
 } from "@odoo/owl";
 
+import { browser } from "@web/core/browser/browser";
 import { Dropdown } from "@web/core/dropdown/dropdown";
 import { _t } from "@web/core/l10n/translation";
 import { usePopover } from "@web/core/popover/popover_hook";
@@ -34,6 +35,8 @@ import { escape } from "@web/core/utils/strings";
 import { useThrottleForAnimation } from "@web/core/utils/timing";
 import { FileUploader } from "@web/views/fields/file_handler";
 
+export const DELAY_FOR_SPINNER = 1000;
+
 /**
  * @typedef {Object} Props
  * @property {function} [close]
@@ -82,6 +85,8 @@ export class Chatter extends Component {
         isInFormSheetBg: true,
         threadId: false,
     };
+    /** @type {number|null} */
+    loadingAttachmentTimeout = null;
 
     setup() {
         this.action = useService("action");
@@ -97,6 +102,7 @@ export class Chatter extends Component {
             isAttachmentBoxOpened: this.props.isAttachmentBoxVisibleInitially,
             jumpThreadPresent: 0,
             showActivities: true,
+            showAttachmentLoading: false,
             /** @type {import("@mail/core/common/thread_model").Thread} */
             thread: undefined,
         });
@@ -169,6 +175,21 @@ export class Chatter extends Component {
             },
             () => [this.state.isAttachmentBoxOpened]
         );
+        useEffect(
+            () => {
+                browser.clearTimeout(this.loadingAttachmentTimeout);
+                if (this.state.thread?.isLoadingAttachments) {
+                    this.loadingAttachmentTimeout = browser.setTimeout(
+                        () => (this.state.showAttachmentLoading = true),
+                        DELAY_FOR_SPINNER
+                    );
+                } else {
+                    this.state.showAttachmentLoading = false;
+                }
+                return () => browser.clearTimeout(this.loadingAttachmentTimeout);
+            },
+            () => [this.state.thread?.isLoadingAttachments]
+        );
     }
 
     /**
diff --git a/addons/mail/static/src/core/web/chatter.xml b/addons/mail/static/src/core/web/chatter.xml
index bdbffbbb364..e2e760c3179 100644
--- a/addons/mail/static/src/core/web/chatter.xml
+++ b/addons/mail/static/src/core/web/chatter.xml
@@ -138,7 +138,7 @@
     <button class="btn btn-link text-action px-1 d-flex align-items-center" aria-label="Attach files" t-att-class="{ 'my-2': !props.compactHeight }" t-on-click="onClickAddAttachments">
         <i class="fa fa-paperclip fa-lg me-1"/>
         <span t-if="attachments.length > 0" t-esc="attachments.length"/>
-        <i t-if="!state.thread.areAttachmentsLoaded and state.thread.isLoadingAttachments" class="fa fa-circle-o-notch fa-spin" aria-label="Attachment counter loading..."/>
+        <i t-if="!state.thread.areAttachmentsLoaded and state.thread.isLoadingAttachments and state.showAttachmentLoading" class="fa fa-circle-o-notch fa-spin" aria-label="Attachment counter loading..."/>
     </button>
 </t>
 
diff --git a/addons/mail/static/tests/web/chatter_tests.js b/addons/mail/static/tests/web/chatter_tests.js
index 065ccacfd89..604ea9162ba 100644
--- a/addons/mail/static/tests/web/chatter_tests.js
+++ b/addons/mail/static/tests/web/chatter_tests.js
@@ -12,6 +12,7 @@ import {
     startServer,
     waitUntil,
 } from "@mail/../tests/helpers/test_utils";
+import { DELAY_FOR_SPINNER } from "@mail/core/web/chatter";
 
 import { editInput, triggerHotkey } from "@web/../tests/helpers/utils";
 import { file } from "@web/../tests/legacy/helpers/test_utils";
@@ -130,7 +131,8 @@ QUnit.test("No attachment loading spinner when creating records", async (assert)
 QUnit.test(
     "No attachment loading spinner when switching from loading record to creation of record",
     async (assert) => {
-        const { openFormView, pyEnv } = await start({
+        const { advanceTime, openFormView, pyEnv } = await start({
+            hasTimeControl: true,
             async mockRPC(route) {
                 if (route === "/mail/thread/data") {
                     await new Promise(() => {});
@@ -139,7 +141,8 @@ QUnit.test(
         });
         const partnerId = pyEnv["res.partner"].create({ name: "John" });
         await openFormView("res.partner", partnerId, { waitUntilDataLoaded: false });
-        assert.containsOnce($, "button[aria-label='Attach files'] .fa-spin");
+        await advanceTime(DELAY_FOR_SPINNER);
+        await waitUntil("button[aria-label='Attach files'] .fa-spin");
         await click(".o_form_button_create");
         assert.containsNone($, "button[aria-label='Attach files'] .fa-spin");
     }
diff --git a/addons/mail/static/tests/web/chatter_topbar_tests.js b/addons/mail/static/tests/web/chatter_topbar_tests.js
index f066ad49de4..b2d1c33d3ac 100644
--- a/addons/mail/static/tests/web/chatter_topbar_tests.js
+++ b/addons/mail/static/tests/web/chatter_topbar_tests.js
@@ -6,7 +6,9 @@ import {
     nextAnimationFrame,
     start,
     startServer,
+    waitUntil,
 } from "@mail/../tests/helpers/test_utils";
+import { DELAY_FOR_SPINNER } from "@mail/core/web/chatter";
 
 import { makeDeferred } from "@web/../tests/helpers/utils";
 
@@ -181,7 +183,8 @@ QUnit.test("attachment counter with attachments", async (assert) => {
 QUnit.test("attachment counter while loading attachments", async (assert) => {
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
-    const { openView } = await start({
+    const { advanceTime, openView } = await start({
+        hasTimeControl: true,
         async mockRPC(route) {
             if (route.includes("/mail/thread/data")) {
                 await makeDeferred(); // simulate long loading
@@ -193,7 +196,8 @@ QUnit.test("attachment counter while loading attachments", async (assert) => {
         res_model: "res.partner",
         views: [[false, "form"]],
     });
-    assert.containsOnce($, "button[aria-label='Attach files'] .fa-spin");
+    await advanceTime(DELAY_FOR_SPINNER);
+    await waitUntil("button[aria-label='Attach files'] .fa-spin");
     assert.containsNone($, "button[aria-label='Attach files']:contains(0)");
 });
 
@@ -201,7 +205,8 @@ QUnit.test("attachment counter transition when attachments become loaded", async
     const pyEnv = await startServer();
     const partnerId = pyEnv["res.partner"].create({});
     const deferred = makeDeferred();
-    const { openView } = await start({
+    const { advanceTime, openView } = await start({
+        hasTimeControl: true,
         async mockRPC(route) {
             if (route.includes("/mail/thread/data")) {
                 await deferred;
@@ -213,7 +218,8 @@ QUnit.test("attachment counter transition when attachments become loaded", async
         res_model: "res.partner",
         views: [[false, "form"]],
     });
-    assert.containsOnce($, "button[aria-label='Attach files'] .fa-spin");
+    await advanceTime(DELAY_FOR_SPINNER);
+    await waitUntil("button[aria-label='Attach files'] .fa-spin");
 
     await afterNextRender(() => deferred.resolve());
     assert.containsNone($, "button[aria-label='Attach files'] .fa-spin");