diff --git a/apps/web/src/components/settings/SettingsPanels.tsx b/apps/web/src/components/settings/SettingsPanels.tsx
index 99287438ab33512fc945b902a90453ebbafd2a62..3c0a25d18b096c073ffe671be9d38d19d89dea2b 100644
--- a/apps/web/src/components/settings/SettingsPanels.tsx
+++ b/apps/web/src/components/settings/SettingsPanels.tsx
@@ -424,6 +424,7 @@ export function useSettingsRestore(onRestored?: () => void) {
       timestampFormat: DEFAULT_UNIFIED_SETTINGS.timestampFormat,
       diffWordWrap: DEFAULT_UNIFIED_SETTINGS.diffWordWrap,
       diffIgnoreWhitespace: DEFAULT_UNIFIED_SETTINGS.diffIgnoreWhitespace,
+      sidebarThreadPreviewCount: DEFAULT_UNIFIED_SETTINGS.sidebarThreadPreviewCount,
       autoOpenPlanSidebar: DEFAULT_UNIFIED_SETTINGS.autoOpenPlanSidebar,
       enableAssistantStreaming: DEFAULT_UNIFIED_SETTINGS.enableAssistantStreaming,
       defaultThreadEnvMode: DEFAULT_UNIFIED_SETTINGS.defaultThreadEnvMode,
diff --git a/packages/contracts/src/settings.ts b/packages/contracts/src/settings.ts
index 15f13e539ea05dfc26411ca06243bfb8bdcf52dc..29231e2f5f323362a247d4664b5cc8dd0a15b274 100644
--- a/packages/contracts/src/settings.ts
+++ b/packages/contracts/src/settings.ts
@@ -497,6 +497,7 @@ export const ClientSettingsPatch = Schema.Struct({
   ),
   sidebarProjectSortOrder: Schema.optionalKey(SidebarProjectSortOrder),
   sidebarThreadSortOrder: Schema.optionalKey(SidebarThreadSortOrder),
+  sidebarThreadPreviewCount: Schema.optionalKey(SidebarThreadPreviewCount),
   timestampFormat: Schema.optionalKey(TimestampFormat),
 });
 export type ClientSettingsPatch = typeof ClientSettingsPatch.Type;