diff --git a/dev/App/User.js b/dev/App/User.js
index cbfaf8723..ba1514a39 100644
--- a/dev/App/User.js
+++ b/dev/App/User.js
@@ -183,7 +183,7 @@ export class AppUser extends AbstractApp {
 		super.bootstart();
 
 		addEventListener('beforeunload', event => {
-			if (arePopupsVisible() || (!SettingsUserStore.layout() && MessageUserStore.message())) {
+			if (arePopupsVisible() || (!SettingsUserStore.usePreviewPane() && MessageUserStore.message())) {
 				event.preventDefault();
 				return event.returnValue = i18n('POPUPS_ASK/EXIT_ARE_YOU_SURE');
 			}
diff --git a/dev/Stores/User/Settings.js b/dev/Stores/User/Settings.js
index e72cd4ab7..d1d12bb5f 100644
--- a/dev/Stores/User/Settings.js
+++ b/dev/Stores/User/Settings.js
@@ -50,10 +50,10 @@ export const SettingsUserStore = new class {
 
 		self.init();
 
-		self.usePreviewPane = koComputable(() => self.layout() && !ThemeStore.isMobile());
+		self.usePreviewPane = koComputable(() => ThemeStore.isMobile() ? 0 : self.layout());
 
 		const toggleLayout = () => {
-			const value = ThemeStore.isMobile() ? 0 : self.layout();
+			const value = self.usePreviewPane();
 			$htmlCL.toggle('sm-msgView-side', Layout.SidePreview === value);
 			$htmlCL.toggle('sm-msgView-bottom', Layout.BottomPreview === value);
 			fireEvent('rl-layout', value);
diff --git a/dev/View/User/MailBox/MessageList.js b/dev/View/User/MailBox/MessageList.js
index 670e5890e..e809f3955 100644
--- a/dev/View/User/MailBox/MessageList.js
+++ b/dev/View/User/MailBox/MessageList.js
@@ -566,11 +566,9 @@ export class MailMessageList extends AbstractViewRight {
 			// initMailboxLayoutResizer
 			const top = dom.querySelector('.messageList'),
 				fToggle = () => {
-					let layout = SettingsUserStore.layout();
+					let layout = SettingsUserStore.usePreviewPane();
 					setLayoutResizer(top, ClientSideKeyNameMessageListSize,
-						(ThemeStore.isMobile() || !layout)
-							? 0
-							: (Layout.SidePreview === layout ? 'Width' : 'Height')
+						layout ? (Layout.SidePreview === layout ? 'Width' : 'Height') : 0
 					);
 				};
 			if (top) {