diff --git a/e2e/tests/journeys.spec.ts b/e2e/tests/journeys.spec.ts
index 936dfe2..1fee453 100644
--- a/e2e/tests/journeys.spec.ts
+++ b/e2e/tests/journeys.spec.ts
@@ -19,6 +19,27 @@ function schoolLinks(page: Page) {
   return page.locator('a[href^="/school/"]');
 }
 
+/**
+ * Two URNs guaranteed to be pure-primary (same phase). The compare page's
+ * phase tabs split all-through schools (which carry KS4 data) onto the
+ * secondary tab, so picking two arbitrary "primary" search hits can land
+ * them on different tabs where only the active one renders. Selecting via
+ * the API by exact phase keeps both on the same tab. Data-invariant: uses
+ * whatever primaries the environment holds.
+ */
+async function twoPrimaryUrns(page: Page): Promise<[string, string]> {
+  const res = await page.request.get('/api/schools?search=primary&per_page=50');
+  expect(res.ok()).toBeTruthy();
+  const body = await res.json();
+  const urns: string[] = (body.schools ?? [])
+    .filter((s: { phase?: string; rwm_expected_pct?: number | null }) =>
+      s.phase === 'Primary' && s.rwm_expected_pct != null,
+    )
+    .map((s: { urn: number }) => String(s.urn));
+  expect(urns.length).toBeGreaterThanOrEqual(2);
+  return [urns[0], urns[1]];
+}
+
 test('home page loads with hero search', async ({ page }) => {
   await page.goto('/');
   await expect(page.locator('h1').first()).toBeVisible();
@@ -139,19 +160,13 @@ test('results map fullscreen falls back to an overlay on iOS', async ({ page })
 });
 
 test('comparing two schools shows the parent-first sections side by side', async ({ page }) => {
-  // Collect two school URNs from search results, then load the share URL
-  await searchByName(page, 'primary');
-  await expect(schoolLinks(page).first()).toBeVisible({ timeout: 15_000 });
-  const hrefs = await schoolLinks(page).evaluateAll((links) =>
-    links.map((l) => (l as HTMLAnchorElement).getAttribute('href') || '')
-  );
-  const urns = [...new Set(hrefs.map((h) => h.match(/\/school\/(\d+)/)?.[1]).filter(Boolean))];
-  expect(urns.length).toBeGreaterThanOrEqual(2);
+  // Two same-phase (pure primary) schools so both stay on one tab.
+  const [urn0, urn1] = await twoPrimaryUrns(page);
 
-  await page.goto(`/compare?urns=${urns[0]},${urns[1]}`);
+  await page.goto(`/compare?urns=${urn0},${urn1}`);
   // Both schools' detail links should render in the comparison view
-  await expect(page.locator(`a[href*="${urns[0]}"]`).first()).toBeVisible({ timeout: 15_000 });
-  await expect(page.locator(`a[href*="${urns[1]}"]`).first()).toBeVisible();
+  await expect(page.locator(`a[href*="${urn0}"]`).first()).toBeVisible({ timeout: 15_000 });
+  await expect(page.locator(`a[href*="${urn1}"]`).first()).toBeVisible();
 
   // The parent-first sections render in order (data-invariant: headings only)
   for (const heading of [