diff --git a/tests/browser/unseen-restore.mjs b/tests/browser/unseen-restore.mjs
index 73b98a16..aabd8962 100644
--- a/tests/browser/unseen-restore.mjs
+++ b/tests/browser/unseen-restore.mjs
@@ -2,26 +2,53 @@
 //
 // Specs that restore through the API while a page is open check what the page does with a restore it did not see:
 // its next write is refused as "Prompt storage was restored since this dialog opened". But the page's Activity store
-// reads the job list every 15 s (activity-store.mjs POLL_MS), and a read that lands while the restore job runs makes
-// the page follow it: when it finishes, the page is shown again from the restored data (S9, index.mjs
+// reads the job list every 15 s (activity-store.mjs POLL_MS), and a read the server answers while the restore job runs
+// makes the page follow it: when it finishes, the page is shown again from the restored data (S9, index.mjs
 // onRestoreFinished), which closes any open dialog. On a slow runner a restore can take longer than the time left to
 // the next read (CI run 40646112668: the restore took 16 s), so whether the page saw it depended on timing.
 //
-// `unseenRestore` makes it the case these specs mean, every time: while `restoring()` runs, the page's job list reads
-// wait, and they go on once it has answered, so they read the restore as already ended, as a tab that read its job
-// list just before and just after the restore does. A restore that is not seen running never reloads the page.
+// `armUnseenRestores(page)`, before the page loads, passes every job-list read of the page through one route, so it
+// knows which reads the server has not answered yet. `unseenRestore(page, restoring)` then closes the gate, waits
+// for those reads' answers (sent before the restore began, they cannot list it), runs `restoring()`, and only after
+// it has answered lets the held reads go on: they read the restore as already ended, as a tab that read its job list
+// just before and just after the restore does. A restore that is never seen running never reloads the page.
 const JOBS = '**/prompt_manager/jobs';
+const gates = new WeakMap();
+
+/** Route `page`'s job-list reads through the restore gate. Call before the page's first navigation. */
+export async function armUnseenRestores(page) {
+    const gate = { closed: null, inFlight: 0, idle: [] };
+    gates.set(page, gate);
+    await page.route(JOBS, async route => {
+        if (gate.closed) {
+            await gate.closed;
+            return route.fallback();
+        }
+        gate.inFlight += 1;
+        try {
+            const response = await route.fetch();
+            await route.fulfill({ response }).catch(() => {});
+        } catch {
+            await route.abort().catch(() => {});
+        } finally {
+            gate.inFlight -= 1;
+            if (gate.inFlight === 0) for (const resolve of gate.idle.splice(0)) resolve();
+        }
+    });
+}
 
 /** Run `restoring()` (an API restore) unseen by `page`'s Activity store; resolves with what it resolves with. */
 export async function unseenRestore(page, restoring) {
-    let answered;
-    const done = new Promise(resolve => { answered = resolve; });
-    const hold = async route => { await done; await route.fallback(); };
-    await page.route(JOBS, hold);
+    const gate = gates.get(page);
+    if (!gate) throw new Error('armUnseenRestores(page) must run before the page loads');
+    let open;
+    gate.closed = new Promise(resolve => { open = resolve; });
     try {
+        // Reads already on their way were sent before the restore: their answers cannot list it.
+        if (gate.inFlight > 0) await new Promise(resolve => gate.idle.push(resolve));
         return await restoring();
     } finally {
-        answered();
-        await page.unroute(JOBS, hold);
+        gate.closed = null;
+        open();
     }
 }
diff --git a/tests/browser/workspace-history.spec.mjs b/tests/browser/workspace-history.spec.mjs
index 62e12f16..f912a892 100644
--- a/tests/browser/workspace-history.spec.mjs
+++ b/tests/browser/workspace-history.spec.mjs
@@ -1,6 +1,6 @@
 import {startCoverage,saveCoverage} from '../../tools/vendor/browser-coverage.mjs';
 import {test,expect} from './fixtures.mjs';
-import {unseenRestore} from './unseen-restore.mjs';
+import {armUnseenRestores,unseenRestore} from './unseen-restore.mjs';
 import {readFile,writeFile} from 'node:fs/promises';
 import {createHash} from 'node:crypto';
 
@@ -17,7 +17,7 @@ const marker=(page,id,anchor='10')=>recorded(page).locator(`button[data-run-id="
 const exact=async locator=>locator.evaluate(node=>node.textContent);
 
 test.beforeEach(async({page,request,browserName})=>{
-    await startCoverage(page,browserName);page.historyErrors=[];page.on('pageerror',error=>page.historyErrors.push(error.message));
+    await startCoverage(page,browserName);await armUnseenRestores(page);page.historyErrors=[];page.on('pageerror',error=>page.historyErrors.push(error.message));
     const reset=await request.post('/__test__/reset',{data:{chronological_history:true}});await expect(reset).toBeOK();page.fixture=await reset.json();
 });
 test.afterEach(async({page,browserName})=>{await saveCoverage(page,browserName);expect(page.historyErrors).toEqual([]);});
diff --git a/tests/browser/workspace-library-editor.spec.mjs b/tests/browser/workspace-library-editor.spec.mjs
index 9c1affe5..2cc85b25 100644
--- a/tests/browser/workspace-library-editor.spec.mjs
+++ b/tests/browser/workspace-library-editor.spec.mjs
@@ -1,7 +1,7 @@
 import {writeFile} from 'node:fs/promises';
 import {startCoverage,saveCoverage} from '../../tools/vendor/browser-coverage.mjs';
 import {test,expect} from './fixtures.mjs';
-import {unseenRestore} from './unseen-restore.mjs';
+import {armUnseenRestores,unseenRestore} from './unseen-restore.mjs';
 import {captureCanonicalState} from './history-canonical-comparison.mjs';
 import {inventoryOf,mapConcept,diffInventory} from './library-editor-canonical-comparison.mjs';
 
@@ -14,7 +14,7 @@ const RATINGS=[['5','5 / 5'],['4','4 / 5'],['3','3 / 5'],['2','2 / 5'],['1','1 /
 const editorDialog=page=>page.locator('dialog.library-editor');
 
 test.beforeEach(async({page,request,browserName})=>{
-    await startCoverage(page,browserName);
+    await startCoverage(page,browserName);await armUnseenRestores(page);
     const reset=await request.post('/__test__/library-editor/reset',{data:{}});await expect(reset).toBeOK();page.fixture=await reset.json();
     page.editorErrors=[];page.on('pageerror',error=>page.editorErrors.push(error.message));
     page.writes=[];page.on('request',item=>{if(item.method()!=='GET')page.writes.push({method:item.method(),url:new URL(item.url()).pathname,body:item.postDataJSON()});});
diff --git a/tests/browser/workspace-vocabulary.spec.mjs b/tests/browser/workspace-vocabulary.spec.mjs
index de64f728..b9b82da2 100644
--- a/tests/browser/workspace-vocabulary.spec.mjs
+++ b/tests/browser/workspace-vocabulary.spec.mjs
@@ -1,7 +1,7 @@
 import {startCoverage,saveCoverage} from '../../tools/vendor/browser-coverage.mjs';
 import {writeFile} from 'node:fs/promises';
 import {test,expect} from './fixtures.mjs';
-import {unseenRestore} from './unseen-restore.mjs';
+import {armUnseenRestores,unseenRestore} from './unseen-restore.mjs';
 import {captureCanonicalState} from './history-canonical-comparison.mjs';
 import {pageInventoryOf,inventoryOf,diffInventory,mapVocabularyConcept,mapVocabularyDialog} from './vocabulary-canonical-comparison.mjs';
 
@@ -41,7 +41,7 @@ async function expectLibrary(page,{tags='',category='',count}) {
 
 let manifest;
 test.beforeEach(async({page,request,browserName})=>{
-    await startCoverage(page,browserName);manifest=await seed(request);
+    await startCoverage(page,browserName);await armUnseenRestores(page);manifest=await seed(request);
     page.vocabularyErrors=[];page.on('pageerror',error=>page.vocabularyErrors.push(error.message));
 });
 test.afterEach(async({page,browserName})=>{await saveCoverage(page,browserName);expect(page.vocabularyErrors).toEqual([]);});