diff --git a/src/agents/bash-tools.exec.pty-cleanup.test.ts b/src/agents/bash-tools.exec.pty-cleanup.test.ts
index 613c8fd0353..efe6f01d606 100644
--- a/src/agents/bash-tools.exec.pty-cleanup.test.ts
+++ b/src/agents/bash-tools.exec.pty-cleanup.test.ts
@@ -1,9 +1,17 @@
 import { afterEach, expect, test, vi } from "vitest";
 import { resetProcessRegistryForTests } from "./bash-process-registry";
+import { createExecTool } from "./bash-tools.exec";
+
+const { ptySpawnMock } = vi.hoisted(() => ({
+  ptySpawnMock: vi.fn(),
+}));
+
+vi.mock("@lydell/node-pty", () => ({
+  spawn: (...args: unknown[]) => ptySpawnMock(...args),
+}));
 
 afterEach(() => {
   resetProcessRegistryForTests();
-  vi.resetModules();
   vi.clearAllMocks();
 });
 
@@ -11,25 +19,20 @@ test("exec disposes PTY listeners after normal exit", async () => {
   const disposeData = vi.fn();
   const disposeExit = vi.fn();
 
-  vi.doMock("@lydell/node-pty", () => ({
-    spawn: () => {
-      return {
-        pid: 0,
-        write: vi.fn(),
-        onData: (listener: (value: string) => void) => {
-          setTimeout(() => listener("ok"), 0);
-          return { dispose: disposeData };
-        },
-        onExit: (listener: (event: { exitCode: number; signal?: number }) => void) => {
-          setTimeout(() => listener({ exitCode: 0 }), 0);
-          return { dispose: disposeExit };
-        },
-        kill: vi.fn(),
-      };
+  ptySpawnMock.mockImplementation(() => ({
+    pid: 0,
+    write: vi.fn(),
+    onData: (listener: (value: string) => void) => {
+      listener("ok");
+      return { dispose: disposeData };
     },
+    onExit: (listener: (event: { exitCode: number; signal?: number }) => void) => {
+      listener({ exitCode: 0 });
+      return { dispose: disposeExit };
+    },
+    kill: vi.fn(),
   }));
 
-  const { createExecTool } = await import("./bash-tools.exec");
   const tool = createExecTool({ allowBackground: false });
   const result = await tool.execute("toolcall", {
     command: "echo ok",
@@ -46,19 +49,14 @@ test("exec tears down PTY resources on timeout", async () => {
   const disposeExit = vi.fn();
   const kill = vi.fn();
 
-  vi.doMock("@lydell/node-pty", () => ({
-    spawn: () => {
-      return {
-        pid: 0,
-        write: vi.fn(),
-        onData: () => ({ dispose: disposeData }),
-        onExit: () => ({ dispose: disposeExit }),
-        kill,
-      };
-    },
+  ptySpawnMock.mockImplementation(() => ({
+    pid: 0,
+    write: vi.fn(),
+    onData: () => ({ dispose: disposeData }),
+    onExit: () => ({ dispose: disposeExit }),
+    kill,
   }));
 
-  const { createExecTool } = await import("./bash-tools.exec");
   const tool = createExecTool({ allowBackground: false });
   await expect(
     tool.execute("toolcall", {
diff --git a/src/agents/bash-tools.exec.pty-fallback-failure.test.ts b/src/agents/bash-tools.exec.pty-fallback-failure.test.ts
index 7f3be417387..2caad66a83f 100644
--- a/src/agents/bash-tools.exec.pty-fallback-failure.test.ts
+++ b/src/agents/bash-tools.exec.pty-fallback-failure.test.ts
@@ -1,5 +1,6 @@
 import { afterEach, expect, test, vi } from "vitest";
 import { listRunningSessions, resetProcessRegistryForTests } from "./bash-process-registry";
+import { createExecTool } from "./bash-tools.exec";
 
 const { supervisorSpawnMock } = vi.hoisted(() => ({
   supervisorSpawnMock: vi.fn(),
@@ -17,7 +18,6 @@ vi.mock("../process/supervisor/index.js", () => ({
 
 afterEach(() => {
   resetProcessRegistryForTests();
-  vi.resetModules();
   vi.clearAllMocks();
 });
 
@@ -26,7 +26,6 @@ test("exec cleans session state when PTY fallback spawn also fails", async () =>
     .mockRejectedValueOnce(new Error("pty spawn failed"))
     .mockRejectedValueOnce(new Error("child fallback failed"));
 
-  const { createExecTool } = await import("./bash-tools.exec");
   const tool = createExecTool({ allowBackground: false });
 
   await expect(
diff --git a/src/cron/isolated-agent/run.skill-filter.test.ts b/src/cron/isolated-agent/run.skill-filter.test.ts
index 9c0bd4300a8..407918c74ac 100644
--- a/src/cron/isolated-agent/run.skill-filter.test.ts
+++ b/src/cron/isolated-agent/run.skill-filter.test.ts
@@ -166,6 +166,8 @@ vi.mock("../../agents/defaults.js", () => ({
   DEFAULT_PROVIDER: "openai",
 }));
 
+const { runCronIsolatedAgentTurn } = await import("./run.js");
+
 // ---------- helpers ----------
 
 function makeJob(overrides?: Record<string, unknown>) {
@@ -230,8 +232,6 @@ describe("runCronIsolatedAgentTurn — skill filter", () => {
   it("passes agent-level skillFilter to buildWorkspaceSkillSnapshot", async () => {
     resolveAgentSkillsFilterMock.mockReturnValue(["meme-factory", "weather"]);
 
-    const { runCronIsolatedAgentTurn } = await import("./run.js");
-
     const result = await runCronIsolatedAgentTurn(
       makeParams({
         cfg: { agents: { list: [{ id: "scout", skills: ["meme-factory", "weather"] }] } },
@@ -250,8 +250,6 @@ describe("runCronIsolatedAgentTurn — skill filter", () => {
   it("omits skillFilter when agent has no skills config", async () => {
     resolveAgentSkillsFilterMock.mockReturnValue(undefined);
 
-    const { runCronIsolatedAgentTurn } = await import("./run.js");
-
     const result = await runCronIsolatedAgentTurn(
       makeParams({
         cfg: { agents: { list: [{ id: "general" }] } },
@@ -268,8 +266,6 @@ describe("runCronIsolatedAgentTurn — skill filter", () => {
   it("passes empty skillFilter when agent explicitly disables all skills", async () => {
     resolveAgentSkillsFilterMock.mockReturnValue([]);
 
-    const { runCronIsolatedAgentTurn } = await import("./run.js");
-
     const result = await runCronIsolatedAgentTurn(
       makeParams({
         cfg: { agents: { list: [{ id: "silent", skills: [] }] } },
@@ -302,8 +298,6 @@ describe("runCronIsolatedAgentTurn — skill filter", () => {
       isNewSession: true,
     });
 
-    const { runCronIsolatedAgentTurn } = await import("./run.js");
-
     const result = await runCronIsolatedAgentTurn(
       makeParams({
         cfg: { agents: { list: [{ id: "weather-bot", skills: ["weather"] }] } },
@@ -338,8 +332,6 @@ describe("runCronIsolatedAgentTurn — skill filter", () => {
       isNewSession: true,
     });
 
-    const { runCronIsolatedAgentTurn } = await import("./run.js");
-
     const result = await runCronIsolatedAgentTurn(
       makeParams({
         cfg: { agents: { list: [{ id: "weather-bot", skills: ["weather", "meme-factory"] }] } },