diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 11d4830cc..e2451b8c3 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed Chromium-backed tests failing during suite registration when the shared availability probe was still initializing ([#7384](https://github.com/can1357/oh-my-pi/pull/7384) by [@paralin](https://github.com/paralin)).
+
 ## [17.2.4] - 2026-08-01
 
 ### Added
diff --git a/packages/coding-agent/test/tools/browser-attach.test.ts b/packages/coding-agent/test/tools/browser-attach.test.ts
index 905aa614b..ed9afd184 100644
--- a/packages/coding-agent/test/tools/browser-attach.test.ts
+++ b/packages/coding-agent/test/tools/browser-attach.test.ts
@@ -11,7 +11,9 @@ import {
 } from "@oh-my-pi/pi-coding-agent/tools/browser/registry";
 import { acquireTab, releaseTab } from "@oh-my-pi/pi-coding-agent/tools/browser/tab-supervisor";
 import type { Browser, Page, Target } from "puppeteer-core";
-import { CHROMIUM_AVAILABLE } from "./chromium-probe";
+import { chromiumAvailable } from "./chromium-probe";
+
+const CHROMIUM_AVAILABLE = await chromiumAvailable();
 
 interface FakePageOptions {
 	url: string;
diff --git a/packages/coding-agent/test/tools/browser-tab-evaluate.test.ts b/packages/coding-agent/test/tools/browser-tab-evaluate.test.ts
index 5f87c97f2..5d6234d30 100644
--- a/packages/coding-agent/test/tools/browser-tab-evaluate.test.ts
+++ b/packages/coding-agent/test/tools/browser-tab-evaluate.test.ts
@@ -3,7 +3,9 @@ import { Settings } from "@oh-my-pi/pi-coding-agent/config/settings";
 import type { ToolSession } from "@oh-my-pi/pi-coding-agent/sdk";
 import { BrowserTool } from "@oh-my-pi/pi-coding-agent/tools/browser";
 import { getTabsMapForTest } from "@oh-my-pi/pi-coding-agent/tools/browser/tab-supervisor";
-import { CHROMIUM_AVAILABLE } from "./chromium-probe";
+import { chromiumAvailable } from "./chromium-probe";
+
+const CHROMIUM_AVAILABLE = await chromiumAvailable();
 
 function makeSession(): ToolSession {
 	return {
diff --git a/packages/coding-agent/test/tools/chromium-probe.ts b/packages/coding-agent/test/tools/chromium-probe.ts
index c7d5f1e19..c21456040 100644
--- a/packages/coding-agent/test/tools/chromium-probe.ts
+++ b/packages/coding-agent/test/tools/chromium-probe.ts
@@ -17,5 +17,23 @@ async function chromiumCanLaunch(): Promise<boolean> {
 	}
 }
 
-/** Gate for tests that launch a real Chromium: `describe.skipIf(!CHROMIUM_AVAILABLE)`. */
-export const CHROMIUM_AVAILABLE = await chromiumCanLaunch();
+let probe: Promise<boolean> | undefined;
+
+/**
+ * Gate for tests that launch a real Chromium:
+ *
+ *     const CHROMIUM_AVAILABLE = await chromiumAvailable();
+ *     describe.skipIf(!CHROMIUM_AVAILABLE)(…);
+ *
+ * The result is a promise rather than an awaited `export const`. A module whose
+ * exports are initialized by top-level await hands the test runner a binding
+ * that is still in its temporal dead zone when a second test file in the same
+ * process imports it, and that file dies during registration with "Cannot
+ * access 'CHROMIUM_AVAILABLE' before initialization". Awaiting in the importer
+ * makes the wait part of that file's own evaluation, which the runner does
+ * sequence. The probe runs once per process.
+ */
+export function chromiumAvailable(): Promise<boolean> {
+	probe ??= chromiumCanLaunch();
+	return probe;
+}