diff --git a/README.md b/README.md
index 6b1c28b..2c018e0 100644
--- a/README.md
+++ b/README.md
@@ -381,11 +381,13 @@ handler on a reserved-TLD origin, gets `window.ethereum` from the shipped
 the runner and compared against the active address, the transaction assertions
 run against the raw signed transaction captured at `eth_sendRawTransaction`
 rather than against anything the extension reported, rejecting each prompt is
-required to return a rejection to the page rather than hang or resolve, and the
-password is required to be absent from every message the approval window sends
-to the background — with the message that would carry it required to be present,
-so that check cannot pass by observing nothing. That last one is the standing
-floor under [#157](https://git.eeqj.de/sneak/AutistMask/issues/157).
+required to return a rejection to the page rather than hang or resolve, a prompt
+raised while another approval window has focus is required to open a window of
+its own, and the password is required to be absent from every message the
+approval window sends to the background — with the message that would carry it
+required to be present, so that check cannot pass by observing nothing. That
+last one is the standing floor under
+[#157](https://git.eeqj.de/sneak/AutistMask/issues/157).
 
 Two limits of that coverage, neither of them papered over. The RPC is stubbed
 throughout, so this is **not** a real dApp against a real network with real
@@ -619,12 +621,9 @@ The jobs **report, they do not gate.** A failure is a red mark against the
 commit that a reviewer has to account for, not a hard block: whether a check
 blocks a merge is Gitea branch protection, which this repo does not configure.
 
-That is not only a statement about configuration. A report of the Chrome suite
-**failing under load** is still open:
-[#290](https://git.eeqj.de/sneak/AutistMask/issues/290), runs on a busy machine
-failing with `the extension opened no approval window within 30000ms`. So a red
-`e2e-chrome` has to be read before it is believed, and those failures are the
-blocker to ever making this a required check. Do not answer them with a retry
+That is not only a statement about configuration. No report of the Chrome suite
+**failing under load** is open now, but it has failed that way before, so a red
+`e2e-chrome` is read before it is believed. Do not answer one with a retry
 wrapper: a suite that reruns until it is green stops being evidence.
 
 Nothing in either job can pass vacuously. There is no `continue-on-error` and no
@@ -1940,7 +1939,8 @@ view would leave a wallet one click from deletion.
   `eth_sendTransaction` arriving while one is unanswered is refused with
   EIP-1193 code `-32002` rather than being populated at the same nonce. It opens
   no window and takes no nonce, and the site can send it again once the pending
-  one is answered.
+  one is answered. The window is centred on the browser window the user was last
+  in, never on another approval window still open.
 - **Elements**:
     - "Transaction Request" heading
     - Phishing warning banner (shown when the hostname is on the phishing
diff --git a/TODO.md b/TODO.md
index 333ef45..143b06e 100644
--- a/TODO.md
+++ b/TODO.md
@@ -45,6 +45,17 @@ but the review is broader than any of them.
 
 # Completed Steps
 
+- 2026-10-05: A prompt raised while another approval window has focus opens a
+  window of its own ([#290](https://git.eeqj.de/sneak/AutistMask/issues/290)).
+  The background centred each approval window on the last focused window, which
+  could be an earlier approval window still open; headless Chrome reports one as
+  1280x720, so the new window came out where the browser refused to create it,
+  and the request failed with no window at all. It now centres on the last
+  focused browser window. In the Chrome end-to-end suite a test could raise its
+  prompt while the previous test's window was still closing, and then either hit
+  that refusal or take the closing window for its own; the runner now closes
+  every approval window between tests.
+
 - 2026-10-05: The e2e suite waits for a save to land before it closes the popup
   ([#446](https://git.eeqj.de/sneak/AutistMask/issues/446)). The Settings round
   trip switched the theme and the network and closed the popup at once, and a
diff --git a/src/background/index.js b/src/background/index.js
index ff432b9..8ff943d 100644
--- a/src/background/index.js
+++ b/src/background/index.js
@@ -423,9 +423,14 @@ async function openApprovalWindow(id) {
     const popupWidth = 360;
     const popupHeight = 600;
 
+    // Centred on the browser window the user was last in, never on a popup.
+    // A popup here is another approval window still open, and centring on
+    // one can give a position the browser refuses ("Bounds must be at least
+    // 50% within visible screen space"): headless Chrome reports this 360x600
+    // popup as 1280x720. The request then failed with no window at all.
     let currentWin = null;
     try {
-        currentWin = await windowsGetLastFocused();
+        currentWin = await windowsGetLastFocused({ windowTypes: ["normal"] });
     } catch {
         // Nothing focused to centre on. The window still opens, at whatever
         // position the browser picks.
diff --git a/src/shared/browserApi.js b/src/shared/browserApi.js
index c512286..8a5c64c 100644
--- a/src/shared/browserApi.js
+++ b/src/shared/browserApi.js
@@ -244,10 +244,11 @@ function windowsCreate(createData) {
 }
 
 /**
- * @returns {Promise<Object>} the last focused window.
+ * @param {Object} queryOptions which windows count, e.g. `windowTypes`.
+ * @returns {Promise<Object>} the last focused of those windows.
  */
-function windowsGetLastFocused() {
-    return invoke(windowsApi(), "getLastFocused");
+function windowsGetLastFocused(queryOptions) {
+    return invoke(windowsApi(), "getLastFocused", queryOptions);
 }
 
 /**
diff --git a/tests/backgroundApproval.test.js b/tests/backgroundApproval.test.js
index 7cdfb02..eef0270 100644
--- a/tests/backgroundApproval.test.js
+++ b/tests/backgroundApproval.test.js
@@ -267,7 +267,14 @@ function loadBackground(options) {
             lastError: null,
         },
         windows: {
-            getLastFocused: (cb) => cb(null),
+            // The last focused of `opts.windows` (listed oldest focus first)
+            // whose type the caller asked for, as the browser filters them.
+            getLastFocused: (queryOptions, cb) => {
+                const asked = (opts.windows || []).filter((w) =>
+                    queryOptions.windowTypes.includes(w.type),
+                );
+                cb(asked[asked.length - 1] || null);
+            },
             create: (options2, cb) => {
                 created.push(options2);
                 // A browser that answers with no window at all. The approval
@@ -2716,3 +2723,26 @@ describe("removing a site in Settings disconnects it", () => {
         expect(await siteAccounts(bg)).toEqual({ result: [signer.address] });
     });
 });
+
+// An approval window still open is often the last focused window, and headless
+// Chrome reports one as 1280x720. Centred on that, the next approval window
+// lands where the browser refuses to create it, and its request failed with no
+// window at all (https://git.eeqj.de/sneak/AutistMask/issues/290).
+describe("where an approval window opens", () => {
+    test("centred on the browser window, not on an approval window focused since", async () => {
+        const bg = loadBackground({
+            windows: [
+                { type: "normal", left: 0, top: 0, width: 1280, height: 720 },
+                { type: "popup", left: 440, top: 0, width: 1280, height: 720 },
+            ],
+        });
+
+        bg.requestSign();
+        await settle();
+
+        // Centred on the browser window; on the approval window it would be at
+        // left 900, the position the browser refused.
+        expect(bg.created).toHaveLength(1);
+        expect(bg.created[0]).toMatchObject({ left: 460, top: 60 });
+    });
+});
diff --git a/tests/backgroundStateIsolation.test.js b/tests/backgroundStateIsolation.test.js
index ef34d04..21ee707 100644
--- a/tests/backgroundStateIsolation.test.js
+++ b/tests/backgroundStateIsolation.test.js
@@ -179,7 +179,7 @@ function loadWorker(networkId, opts) {
             lastError: null,
         },
         windows: {
-            getLastFocused: (cb) => cb(null),
+            getLastFocused: (queryOptions, cb) => cb(null),
             create: (createOpts, cb) => {
                 createdUrls.push(createOpts.url);
                 cb({ id: createdUrls.length });
diff --git a/tests/chainSwitchGate.test.js b/tests/chainSwitchGate.test.js
index 1c94b53..b655957 100644
--- a/tests/chainSwitchGate.test.js
+++ b/tests/chainSwitchGate.test.js
@@ -109,7 +109,7 @@ function loadBackground() {
             lastError: null,
         },
         windows: {
-            getLastFocused: (cb) => cb(null),
+            getLastFocused: (queryOptions, cb) => cb(null),
             create: (options, cb) => cb({ id: 1 }),
             remove: (id, cb) => {
                 if (cb) cb();
diff --git a/tests/coldWorkerChainId.test.js b/tests/coldWorkerChainId.test.js
index 77331fb..812e3e6 100644
--- a/tests/coldWorkerChainId.test.js
+++ b/tests/coldWorkerChainId.test.js
@@ -113,7 +113,7 @@ function loadColdWorker(networkId, opts) {
             lastError: null,
         },
         windows: {
-            getLastFocused: (cb) => cb(null),
+            getLastFocused: (queryOptions, cb) => cb(null),
             create: (options, cb) => cb({ id: 1 }),
             remove: (id, cb) => {
                 if (cb) cb();
diff --git a/tests/coldWorkerChainSwitch.test.js b/tests/coldWorkerChainSwitch.test.js
index 56b5481..2da4a7e 100644
--- a/tests/coldWorkerChainSwitch.test.js
+++ b/tests/coldWorkerChainSwitch.test.js
@@ -105,7 +105,7 @@ function loadColdWorker(networkId) {
             lastError: null,
         },
         windows: {
-            getLastFocused: (cb) => cb(null),
+            getLastFocused: (queryOptions, cb) => cb(null),
             create: (options, cb) => cb({ id: 1 }),
             remove: (id, cb) => {
                 if (cb) cb();
diff --git a/tests/coldWorkerSendTransaction.test.js b/tests/coldWorkerSendTransaction.test.js
index 1344807..ecee656 100644
--- a/tests/coldWorkerSendTransaction.test.js
+++ b/tests/coldWorkerSendTransaction.test.js
@@ -148,7 +148,7 @@ function loadColdWorker(networkId) {
             lastError: null,
         },
         windows: {
-            getLastFocused: (cb) => cb(null),
+            getLastFocused: (queryOptions, cb) => cb(null),
             create: (opts, cb) => {
                 createdUrls.push(opts.url);
                 cb({ id: createdUrls.length });
diff --git a/tests/e2e/run.js b/tests/e2e/run.js
index 7f022c8..ff20a49 100644
--- a/tests/e2e/run.js
+++ b/tests/e2e/run.js
@@ -2676,7 +2676,9 @@ function dappMessages(page, type) {
 
 // The approval window the background opened. Approvals are raised from an
 // RPC call rather than from a user gesture, so the extension opens a real
-// popup window for them; it is an ordinary page in this context.
+// popup window for them; it is an ordinary page in this context. It is the
+// first one found: the runner closes every approval window between tests, so
+// within a test it can only be this test's.
 async function waitForApprovalWindow(ctx, timeout = 30000) {
     const deadline = Date.now() + timeout;
     for (;;) {
@@ -3633,6 +3635,55 @@ test("eth_sendTransaction rejected broadcasts nothing (#183)", async (env) => {
     );
 });
 
+// The extension used to centre every approval window on the last focused
+// window. Centred on another approval window, the new one landed where the
+// browser refused to create it, and the request failed with no window at all
+// (https://git.eeqj.de/sneak/AutistMask/issues/290).
+test("a prompt raised while another approval window has focus opens its own (#290)", async (env) => {
+    await startRequest(env.dapp, "focus-sign", "personal_sign", [
+        SIGN_HEX,
+        env.expectedAddress,
+    ]);
+    const signWindow = await waitForApprovalWindow(env.ctx);
+    await visible(signWindow, "#view-approve-sign");
+    await signWindow.bringToFront();
+    const focused = await env.page.evaluate(
+        () =>
+            new Promise((resolve) => {
+                chrome.windows.getLastFocused((w) => resolve(w.type));
+            }),
+    );
+    assert(
+        focused === "popup",
+        "the sign window does not have focus, so this proves nothing: the " +
+            "last focused window is a " +
+            focused,
+    );
+
+    const opened = env.ctx.waitForEvent("page");
+    await startRequest(env.dapp, "focus-tx", "eth_sendTransaction", [
+        {
+            from: env.expectedAddress,
+            to: STUB_COUNTERPARTY,
+            value: toQuantity(TX_VALUE_WEI),
+            data: TX_DATA,
+        },
+    ]);
+    const txWindow = await opened.catch(async () => {
+        const outcome = await settleRequest(env.dapp, "focus-tx", 1000);
+        throw new Error(
+            "the extension opened no window for the transaction: " +
+                JSON.stringify(outcome),
+        );
+    });
+    await visible(txWindow, "#view-approve-tx");
+
+    // Closing a window is refusing its prompt, so both answer 4001.
+    await closeApprovalPages(env.ctx);
+    await assertUserRejection(env.dapp, "focus-tx", "the transaction prompt");
+    await assertUserRejection(env.dapp, "focus-sign", "the sign prompt");
+});
+
 // The closing pass over both boundaries at once. Every message the section
 // put on either channel is re-read here and required to be free of the
 // password — and required to be there at all, method by method, so the
@@ -4002,6 +4053,13 @@ async function main() {
             failure = e.message;
         }
 
+        // No test starts with an approval window open. One that closes itself,
+        // after a signature or on Reject, can still be closing when the next
+        // test raises its prompt, and waitForApprovalWindow() would take it
+        // for the new one; one a failed test left unanswered would refuse the
+        // next prompt from its site.
+        await closeApprovalPages(env.ctx);
+
         // Any uncaught page error, console.error or unstubbed request
         // fails the test that provoked it, whether or not its assertions
         // passed. This is the mechanism that caught #150.
diff --git a/tests/stateUnusableRpc.test.js b/tests/stateUnusableRpc.test.js
index 66fd70a..6a9c6de 100644
--- a/tests/stateUnusableRpc.test.js
+++ b/tests/stateUnusableRpc.test.js
@@ -109,7 +109,7 @@ function loadColdWorker(stored) {
             lastError: null,
         },
         windows: {
-            getLastFocused: (cb) => cb(null),
+            getLastFocused: (queryOptions, cb) => cb(null),
             create: (options, cb) => cb({ id: 1 }),
             remove: (id, cb) => {
                 if (cb) cb();