diff --git a/src/renderer/src/lib/worktree-reactivation-tab-forkbomb.test.ts b/src/renderer/src/lib/worktree-reactivation-tab-forkbomb.test.ts
new file mode 100644
index 000000000..a0c24f245
--- /dev/null
+++ b/src/renderer/src/lib/worktree-reactivation-tab-forkbomb.test.ts
@@ -0,0 +1,101 @@
+import path from 'node:path'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { useAppStore, type AppState } from '@/store'
+import { activateAndRevealWorktree } from './worktree-activation'
+import { makeCreatedAgentWorktree as makeWorktree } from '@/lib/worktree-activation-created-agent-test-state'
+
+const initialAppStoreState = useAppStore.getState()
+
+function baseState(worktree: ReturnType<typeof makeWorktree>): Partial<AppState> {
+  return {
+    repos: [
+      {
+        id: 'repo-1',
+        path: path.join(path.sep, 'workspace', 'repo'),
+        displayName: 'repo',
+        badgeColor: '#000000',
+        addedAt: 0
+      }
+    ],
+    worktreesByRepo: { 'repo-1': [worktree] },
+    activeRepoId: 'repo-1',
+    activeView: 'terminal',
+    tabsByWorktree: {},
+    unifiedTabsByWorktree: {},
+    groupsByWorktree: {},
+    layoutByWorktree: {},
+    activeGroupIdByWorktree: {},
+    openFiles: [],
+    browserTabsByWorktree: {},
+    activeFileIdByWorktree: {},
+    activeBrowserTabIdByWorktree: {},
+    activeTabTypeByWorktree: {},
+    activeTabIdByWorktree: {},
+    tabBarOrderByWorktree: {},
+    pendingStartupByTabId: {},
+    automaticAgentResumeClaimsByTabId: {},
+    agentStatusByPaneKey: {},
+    sleepingAgentSessionsByPaneKey: {},
+    settings: {
+      agentCmdOverrides: {},
+      setupScriptLaunchMode: 'new-tab'
+    } as unknown as ReturnType<typeof useAppStore.getState>['settings'],
+    markWorktreeVisited: vi.fn(),
+    recordWorktreeVisit: vi.fn(),
+    refreshGitHubForWorktreeIfStale: vi.fn(),
+    revealWorktreeInSidebar: vi.fn()
+  }
+}
+
+afterEach(() => {
+  useAppStore.setState(initialAppStoreState, true)
+})
+
+describe('STA-1111 worktree reopen does not fork-bomb tabs', () => {
+  it('re-captured sleeping codex session resumes once, not once per reopen', () => {
+    const worktree = { ...makeWorktree(), createdWithAgent: undefined }
+    useAppStore.setState(baseState(worktree))
+    const providerSession = { key: 'session_id' as const, id: 'codex-session-1' }
+    let resumedTabId: string | undefined
+
+    for (let reopen = 0; reopen < 4; reopen++) {
+      const paneKey = `slept-pane-${reopen}:0`
+      useAppStore.setState((s) => ({
+        sleepingAgentSessionsByPaneKey: {
+          ...s.sleepingAgentSessionsByPaneKey,
+          [paneKey]: {
+            paneKey,
+            tabId: `slept-pane-${reopen}`,
+            worktreeId: worktree.id,
+            agent: 'codex',
+            providerSession,
+            prompt: 'resume prior task',
+            state: 'working',
+            origin: 'live',
+            capturedAt: 1000 + reopen,
+            updatedAt: 1000 + reopen,
+            terminalTitle: 'Codex'
+          }
+        }
+      }))
+
+      activateAndRevealWorktree(worktree.id)
+      const state = useAppStore.getState()
+      const tabs = state.tabsByWorktree[worktree.id] ?? []
+
+      expect(tabs).toHaveLength(1)
+      resumedTabId ??= tabs[0]!.id
+      expect(tabs[0]!.id).toBe(resumedTabId)
+      expect(state.automaticAgentResumeClaimsByTabId[tabs[0]!.id]?.providerSession).toEqual(
+        providerSession
+      )
+      expect(state.sleepingAgentSessionsByPaneKey[paneKey]).toBeUndefined()
+
+      if (reopen === 0) {
+        expect(state.consumeTabStartupCommand(tabs[0]!.id)?.resumeProviderSession).toEqual(
+          providerSession
+        )
+      }
+    }
+  })
+})