diff --git a/packages/db/src/data/events.ts b/packages/db/src/data/events.ts
index 85af19d14..35e8bbcce 100644
--- a/packages/db/src/data/events.ts
+++ b/packages/db/src/data/events.ts
@@ -1917,20 +1917,25 @@ export function listTodoSnapshotEventRowsForThread(
     "item/completed",
   ] satisfies ThreadEventType[];
 
-  const rows = db
-    .select(storedEventRowFields)
-    .from(events)
-    .where(
-      and(
-        eq(events.threadId, args.threadId),
-        inArray(events.type, itemTypes),
-        eq(events.itemKind, "toolCall"),
-        sql`json_extract(${events.data}, '$.item.tool') IN (
-          'TodoWrite', 'TaskCreate', 'TaskUpdate', 'TaskList', 'TaskGet'
-        )`,
-      ),
-    )
-    .all();
+  // Issue #1131 experiment: pin the tiny partial expression index (created
+  // manually in the seeded db for the experiment) and spell the predicate as
+  // literals so SQLite can prove the partial-index WHERE clause.
+  const rows = db.all<StoredEventRow>(sql`
+    SELECT ${events.createdAt} AS "createdAt", ${events.data} AS "data", ${events.id} AS "id",
+      ${events.itemId} AS "itemId", ${events.itemKind} AS "itemKind",
+      ${events.providerThreadId} AS "providerThreadId", ${events.scopeKind} AS "scopeKind",
+      ${events.sequence} AS "sequence", ${events.threadId} AS "threadId",
+      ${events.turnId} AS "turnId", ${events.type} AS "type"
+    FROM ${events} INDEXED BY events_todo_snapshot_idx
+    WHERE ${events.threadId} = ${args.threadId}
+      AND ${events.type} IN ('item/started', 'item/completed')
+      AND ${events.itemKind} = 'toolCall'
+      AND json_extract(${events.data}, '$.item.tool') IN (
+        'TodoWrite', 'TaskCreate', 'TaskUpdate', 'TaskList', 'TaskGet'
+      )
+    ORDER BY ${events.sequence}
+  `);
+  void itemTypes;
 
   // Ordering in SQL makes SQLite prefer the thread/sequence index and read every
   // event in the thread to satisfy the sort; the type/item-kind index visits