diff --git a/addons/mail/static/src/web/chat_window/chat_window.js b/addons/mail/static/src/web/chat_window/chat_window.js
index b46d6a8645c..700603c914e 100644
--- a/addons/mail/static/src/web/chat_window/chat_window.js
+++ b/addons/mail/static/src/web/chat_window/chat_window.js
@@ -80,11 +80,12 @@ export class ChatWindow extends Component {
     }
 
     get style() {
+        const maxHeight = !this.store.isSmall ? "max-height: 95vh;" : "";
         const textDirection = localization.direction;
         const offsetFrom = textDirection === "rtl" ? "left" : "right";
         const visibleOffset = this.store.isSmall ? 0 : this.props.right;
         const oppositeFrom = offsetFrom === "right" ? "left" : "right";
-        return `${offsetFrom}: ${visibleOffset}px; ${oppositeFrom}: auto`;
+        return `${offsetFrom}: ${visibleOffset}px; ${oppositeFrom}: auto; ${maxHeight}`;
     }
 
     onKeydown(ev) {
@@ -114,6 +115,9 @@ export class ChatWindow extends Component {
     }
 
     toggleFold() {
+        if (this.store.isSmall) {
+            return;
+        }
         if (this.props.chatWindow.hidden) {
             this.chatWindowService.makeVisible(this.props.chatWindow);
         } else {
diff --git a/addons/mail/static/src/web/chat_window/chat_window.scss b/addons/mail/static/src/web/chat_window/chat_window.scss
index 28848e090e3..988139f7aa6 100644
--- a/addons/mail/static/src/web/chat_window/chat_window.scss
+++ b/addons/mail/static/src/web/chat_window/chat_window.scss
@@ -1,5 +1,4 @@
 .o-mail-ChatWindow {
-    max-height: 95vh;
     height: 460px;
     width: $o-mail-ChatWindow-width;
     z-index: 999; // messaging menu is dropdown (1000)
diff --git a/addons/mail/static/src/web/chat_window/chat_window.xml b/addons/mail/static/src/web/chat_window/chat_window.xml
index e0bf156852a..b95d95ff84a 100644
--- a/addons/mail/static/src/web/chat_window/chat_window.xml
+++ b/addons/mail/static/src/web/chat_window/chat_window.xml
@@ -7,12 +7,13 @@
         t-att-class="{
                 'w-100 h-100': store.isSmall,
                 'o-folded': props.chatWindow.folded,
-                'position-absolute bottom-0 rounded-top-3 overflow-hidden d-flex flex-column': !props.chatWindow.hidden
+                'position-absolute bottom-0 overflow-hidden d-flex flex-column': !props.chatWindow.hidden,
+                'rounded-top-3': !props.chatWindow.hidden and !store.isSmall,
                 }"
         t-on-keydown.stop="onKeydown"
         tabindex="1"
     >
-        <div class="o-mail-ChatWindow-header d-flex align-items-center cursor-pointer flex-shrink-0" t-on-click="toggleFold">
+        <div class="o-mail-ChatWindow-header d-flex align-items-center flex-shrink-0" t-on-click="toggleFold" t-att-class="{ 'cursor-pointer': !store.isSmall }">
             <div t-if="store.isSmall" class="cursor-pointer d-flex align-items-center h-100 px-3 py-0 me-2" title="Close conversation" t-on-click="() => this.close()">
                 <i class="fa fa-arrow-left"/>
             </div>
diff --git a/addons/mail/static/tests/chat_window/chat_window_tests.js b/addons/mail/static/tests/chat_window/chat_window_tests.js
index 8d699d47c89..d71c566ce18 100644
--- a/addons/mail/static/tests/chat_window/chat_window_tests.js
+++ b/addons/mail/static/tests/chat_window/chat_window_tests.js
@@ -976,3 +976,18 @@ QUnit.test("folded chat window should hide member-list and settings buttons", as
     assert.containsOnce($, "div[title='Show Member List']");
     assert.containsOnce($, "div[title='Show Call Settings']");
 });
+
+QUnit.test("Chat window in mobile are not foldable", async (assert) => {
+    const pyEnv = await startServer();
+    pyEnv["mail.channel"].create({
+        channel_member_ids: [[0, 0, { fold_state: "open", partner_id: pyEnv.currentPartnerId }]],
+    });
+    patchUiSize({ size: SIZES.SM });
+    await start();
+    await click("button i[aria-label='Messages']");
+    await click(".o-mail-NotificationItem");
+    assert.containsNone($, ".o-mail-ChatWindow-header.cursor-pointer");
+    click(".o-mail-ChatWindow-header").catch(() => {});
+    await nextAnimationFrame();
+    assert.containsOnce($, ".o-mail-ChatWindow-content"); // content => non-folded
+});