diff --git a/src/tools/agent-teams/team-config-store.test.ts b/src/tools/agent-teams/team-config-store.test.ts
new file mode 100644
index 000000000..466f96e71
--- /dev/null
+++ b/src/tools/agent-teams/team-config-store.test.ts
@@ -0,0 +1,48 @@
+/// <reference types="bun-types" />
+import { afterEach, beforeEach, describe, expect, test } from "bun:test"
+import { mkdtempSync, rmSync } from "node:fs"
+import { tmpdir } from "node:os"
+import { join } from "node:path"
+import { acquireLock } from "../../features/claude-tasks/storage"
+import { getTeamDir } from "./paths"
+import { createTeamConfig, deleteTeamData, teamExists } from "./team-config-store"
+
+describe("agent-teams team config store", () => {
+  let originalCwd: string
+  let tempProjectDir: string
+
+  beforeEach(() => {
+    originalCwd = process.cwd()
+    tempProjectDir = mkdtempSync(join(tmpdir(), "agent-teams-config-store-"))
+    process.chdir(tempProjectDir)
+    createTeamConfig("core", "Core team", "ses-main", tempProjectDir, "sisyphus")
+  })
+
+  afterEach(() => {
+    if (teamExists("core")) {
+      deleteTeamData("core")
+    }
+    process.chdir(originalCwd)
+    rmSync(tempProjectDir, { recursive: true, force: true })
+  })
+
+  test("deleteTeamData waits for team lock before removing team files", () => {
+    //#given
+    const lock = acquireLock(getTeamDir("core"))
+    expect(lock.acquired).toBe(true)
+
+    //#when
+    const deleteWhileLocked = () => deleteTeamData("core")
+
+    //#then
+    expect(deleteWhileLocked).toThrow("team_lock_unavailable")
+    expect(teamExists("core")).toBe(true)
+
+    //#when
+    lock.release()
+    deleteTeamData("core")
+
+    //#then
+    expect(teamExists("core")).toBe(false)
+  })
+})
diff --git a/src/tools/agent-teams/team-config-store.ts b/src/tools/agent-teams/team-config-store.ts
index 707659fe6..a57d0b47b 100644
--- a/src/tools/agent-teams/team-config-store.ts
+++ b/src/tools/agent-teams/team-config-store.ts
@@ -173,14 +173,16 @@ export function assignNextColor(config: TeamConfig): string {
 
 export function deleteTeamData(teamName: string): void {
   assertValidTeamName(teamName)
-  const teamDir = getTeamDir(teamName)
-  const taskDir = getTeamTaskDir(teamName)
+  withTeamLock(teamName, () => {
+    const teamDir = getTeamDir(teamName)
+    const taskDir = getTeamTaskDir(teamName)
 
-  if (existsSync(teamDir)) {
-    rmSync(teamDir, { recursive: true, force: true })
-  }
+    if (existsSync(teamDir)) {
+      rmSync(teamDir, { recursive: true, force: true })
+    }
 
-  if (existsSync(taskDir)) {
-    rmSync(taskDir, { recursive: true, force: true })
-  }
+    if (existsSync(taskDir)) {
+      rmSync(taskDir, { recursive: true, force: true })
+    }
+  })
 }