diff --git a/src/agents/compaction.test.ts b/src/agents/compaction.test.ts
index ce273e67e92..f4e04852cd1 100644
--- a/src/agents/compaction.test.ts
+++ b/src/agents/compaction.test.ts
@@ -2,38 +2,7 @@ import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import type { AssistantMessage, ToolResultMessage } from "@mariozechner/pi-ai";
 import { beforeAll, describe, expect, it, vi } from "vitest";
 import { makeAgentAssistantMessage } from "./test-helpers/agent-message-fixtures.js";
-
-const piCodingAgentMocks = vi.hoisted(() => ({
-  estimateTokens: vi.fn((message: unknown) => estimateTokenish(message)),
-}));
-
-function readText(value: unknown): string {
-  if (typeof value === "string") {
-    return value;
-  }
-  if (Array.isArray(value)) {
-    return value.map(readText).join("");
-  }
-  if (value && typeof value === "object") {
-    const record = value as { text?: unknown; content?: unknown; arguments?: unknown };
-    return `${readText(record.text)}${readText(record.content)}${readText(record.arguments)}`;
-  }
-  return "";
-}
-
-function estimateTokenish(message: unknown): number {
-  return Math.max(1, Math.ceil(readText(message).length / 4));
-}
-
-vi.mock("@mariozechner/pi-coding-agent", async () => {
-  const actual = await vi.importActual<typeof import("@mariozechner/pi-coding-agent")>(
-    "@mariozechner/pi-coding-agent",
-  );
-  return {
-    ...actual,
-    estimateTokens: piCodingAgentMocks.estimateTokens,
-  };
-});
+import "./test-helpers/pi-coding-agent-token-mock.js";
 
 let estimateMessagesTokens: typeof import("./compaction.js").estimateMessagesTokens;
 let pruneHistoryForContextShare: typeof import("./compaction.js").pruneHistoryForContextShare;
diff --git a/src/agents/pi-embedded-runner/run/preemptive-compaction.test.ts b/src/agents/pi-embedded-runner/run/preemptive-compaction.test.ts
index 5fcecfb97f7..ab9a0be6470 100644
--- a/src/agents/pi-embedded-runner/run/preemptive-compaction.test.ts
+++ b/src/agents/pi-embedded-runner/run/preemptive-compaction.test.ts
@@ -1,39 +1,8 @@
 import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { beforeAll, describe, expect, it, vi } from "vitest";
+import "../../test-helpers/pi-coding-agent-token-mock.js";
 import { estimateToolResultReductionPotential } from "../tool-result-truncation.js";
 
-const piCodingAgentMocks = vi.hoisted(() => ({
-  estimateTokens: vi.fn((message: unknown) => estimateTokenish(message)),
-}));
-
-function readText(value: unknown): string {
-  if (typeof value === "string") {
-    return value;
-  }
-  if (Array.isArray(value)) {
-    return value.map(readText).join("");
-  }
-  if (value && typeof value === "object") {
-    const record = value as { text?: unknown; content?: unknown };
-    return `${readText(record.text)}${readText(record.content)}`;
-  }
-  return "";
-}
-
-function estimateTokenish(message: unknown): number {
-  return Math.max(1, Math.ceil(readText(message).length / 4));
-}
-
-vi.mock("@mariozechner/pi-coding-agent", async () => {
-  const actual = await vi.importActual<typeof import("@mariozechner/pi-coding-agent")>(
-    "@mariozechner/pi-coding-agent",
-  );
-  return {
-    ...actual,
-    estimateTokens: piCodingAgentMocks.estimateTokens,
-  };
-});
-
 let PREEMPTIVE_OVERFLOW_ERROR_TEXT: typeof import("./preemptive-compaction.js").PREEMPTIVE_OVERFLOW_ERROR_TEXT;
 let estimatePrePromptTokens: typeof import("./preemptive-compaction.js").estimatePrePromptTokens;
 let shouldPreemptivelyCompactBeforePrompt: typeof import("./preemptive-compaction.js").shouldPreemptivelyCompactBeforePrompt;
diff --git a/src/agents/test-helpers/pi-coding-agent-token-mock.ts b/src/agents/test-helpers/pi-coding-agent-token-mock.ts
new file mode 100644
index 00000000000..a9062ddbfd4
--- /dev/null
+++ b/src/agents/test-helpers/pi-coding-agent-token-mock.ts
@@ -0,0 +1,35 @@
+import { vi } from "vitest";
+
+const piCodingAgentTokenMocks = vi.hoisted(() => {
+  function readText(value: unknown): string {
+    if (typeof value === "string") {
+      return value;
+    }
+    if (Array.isArray(value)) {
+      return value.map(readText).join("");
+    }
+    if (value && typeof value === "object") {
+      const record = value as { text?: unknown; content?: unknown; arguments?: unknown };
+      return `${readText(record.text)}${readText(record.content)}${readText(record.arguments)}`;
+    }
+    return "";
+  }
+
+  function estimateTokenish(message: unknown): number {
+    return Math.max(1, Math.ceil(readText(message).length / 4));
+  }
+
+  return {
+    estimateTokens: vi.fn((message: unknown) => estimateTokenish(message)),
+  };
+});
+
+vi.mock("@mariozechner/pi-coding-agent", async () => {
+  const actual = await vi.importActual<typeof import("@mariozechner/pi-coding-agent")>(
+    "@mariozechner/pi-coding-agent",
+  );
+  return {
+    ...actual,
+    estimateTokens: piCodingAgentTokenMocks.estimateTokens,
+  };
+});