diff --git a/src/renderer/src/runtime/web-session-intent-owner.test.ts b/src/renderer/src/runtime/web-session-intent-owner.test.ts
index 137b89ed991..dba9120cc04 100644
--- a/src/renderer/src/runtime/web-session-intent-owner.test.ts
+++ b/src/renderer/src/runtime/web-session-intent-owner.test.ts
@@ -11,6 +11,7 @@ import {
   resetWebSessionFocusIntentForTests
 } from './web-session-focus-intent'
 import {
+  MAX_REORDER_INTENT_PARTITIONS,
   recordWebSessionReorderIntent,
   resetWebSessionReorderIntentForTests,
   resolveWebSessionReorderedOrder
@@ -28,6 +29,37 @@ afterEach(() => {
 })
 
 describe('web session intent ownership', () => {
+  it('bounds unresolved reorder intent churn', () => {
+    for (let index = 0; index < MAX_REORDER_INTENT_PARTITIONS + 4; index += 1) {
+      recordWebSessionReorderIntent(
+        { environmentId: `env-${index}`, pairingRevision: 1 },
+        WORKTREE_ID,
+        'group-1',
+        ['tab-b', 'tab-a'],
+        1_000
+      )
+    }
+
+    expect(
+      resolveWebSessionReorderedOrder(
+        { environmentId: 'env-0', pairingRevision: 1 },
+        WORKTREE_ID,
+        'group-1',
+        ['tab-a', 'tab-b'],
+        1_000
+      )
+    ).toEqual(['tab-a', 'tab-b'])
+    expect(
+      resolveWebSessionReorderedOrder(
+        { environmentId: `env-${MAX_REORDER_INTENT_PARTITIONS + 3}`, pairingRevision: 1 },
+        WORKTREE_ID,
+        'group-1',
+        ['tab-a', 'tab-b'],
+        1_000
+      )
+    ).toEqual(['tab-b', 'tab-a'])
+  })
+
   it('isolates close intents across runtimes and same-id re-pairs', () => {
     recordWebSessionCloseIntent(OWNER_A, WORKTREE_ID, 'host-tab', 1_000)
 
diff --git a/src/renderer/src/runtime/web-session-reorder-intent.ts b/src/renderer/src/runtime/web-session-reorder-intent.ts
index 272ef635fa5..fe7d5d4b952 100644
--- a/src/renderer/src/runtime/web-session-reorder-intent.ts
+++ b/src/renderer/src/runtime/web-session-reorder-intent.ts
@@ -13,6 +13,8 @@
 // rejected RPC) from pinning a stale order forever.
 
 const REORDER_INTENT_TTL_MS = 10_000
+export const MAX_REORDER_INTENT_PARTITIONS = 512
+export const MAX_REORDER_INTENTS_PER_PARTITION = 256
 
 type ReorderIntent = { order: string[]; recordedAt: number }
 
@@ -53,7 +55,24 @@ export function recordWebSessionReorderIntent(
     byGroup = new Map()
     pendingReorderByOwnerAndWorktree.set(partitionKey, byGroup)
   }
+  byGroup.delete(groupId)
   byGroup.set(groupId, { order: [...order], recordedAt: now })
+  while (byGroup.size > MAX_REORDER_INTENTS_PER_PARTITION) {
+    const oldest = byGroup.keys().next()
+    if (oldest.done || oldest.value === groupId) {
+      break
+    }
+    byGroup.delete(oldest.value)
+  }
+  pendingReorderByOwnerAndWorktree.delete(partitionKey)
+  pendingReorderByOwnerAndWorktree.set(partitionKey, byGroup)
+  while (pendingReorderByOwnerAndWorktree.size > MAX_REORDER_INTENT_PARTITIONS) {
+    const oldest = pendingReorderByOwnerAndWorktree.keys().next()
+    if (oldest.done || oldest.value === partitionKey) {
+      break
+    }
+    pendingReorderByOwnerAndWorktree.delete(oldest.value)
+  }
 }
 
 /**