diff --git a/src/queue/processors.ts b/src/queue/processors.ts
index cfd1fcad3e..1b4121f19e 100644
--- a/src/queue/processors.ts
+++ b/src/queue/processors.ts
@@ -1939,17 +1939,22 @@ async function sweepRepoRegate(
   }
   // With an active backlog (regateBacklog > 0), a priority repair PR earns an EXCEPTION to the "yield to
   // backlog" rule above, not a license for the whole sweep to also drag along a full SWEEP_MAX_PRS batch of
-  // ordinary stale PRs -- selectRegateCandidates sorts priority PRs first, so capping max to exactly
-  // priorityPullNumbers.length restricts the candidate set to repairs only. No backlog pressure ⇒ a normal,
-  // full-size sweep as before.
+  // ordinary stale PRs. Repair priority only affects selectRegateCandidates eligibility, not final ordering, so
+  // the backlog path must narrow the input pool to priority repairs before applying the normal stale ordering cap.
+  // No backlog pressure ⇒ a normal, full-size sweep as before.
+  const priorityPullNumberSet = new Set(priorityPullNumbers);
   const repairCandidateLimit =
     priorityPullNumbers.length > 0
       ? regateBacklog > 0
         ? priorityPullNumbers.length
         : Math.max(SWEEP_MAX_PRS, priorityPullNumbers.length)
       : null;
+  const candidatePullRequests =
+    regateBacklog > 0 && priorityPullNumbers.length > 0
+      ? openPullRequests.filter((pr) => priorityPullNumberSet.has(pr.number))
+      : openPullRequests;
   const candidates = selectRegateCandidates({
-    pulls: openPullRequests,
+    pulls: candidatePullRequests,
     now: nowIso(),
     priorityPullNumbers,
     priorityBypassesFreshness: priorityPullNumbers.length > 0,
@@ -2020,7 +2025,6 @@ async function sweepRepoRegate(
   // isScheduledRegateSweepJob (queue-common.ts) misclassifies it as background maintenance and it inherits the
   // exact starvation this priority mechanism exists to avoid. Ordinary stale candidates keep the sweep prefix
   // unchanged.
-  const priorityPullNumberSet = new Set(priorityPullNumbers);
   for (const [index, pr] of candidates.entries()) {
     const others = openPullRequests.filter(
       (other) => other.number !== pr.number,
diff --git a/test/unit/queue.test.ts b/test/unit/queue.test.ts
index cbb9a341e7..b16d1b96f0 100644
--- a/test/unit/queue.test.ts
+++ b/test/unit/queue.test.ts
@@ -7481,15 +7481,22 @@ describe("queue processors", () => {
     await upsertInstallation(env, { action: "created", installation: { id: 9403, account: { login: "owner", id: 1, type: "Organization" }, target_type: "Organization", repository_selection: "selected", permissions: {}, events: [] } });
     await upsertRepositoryFromGitHub(env, { name: "agent-repo", full_name: "owner/agent-repo", private: false, owner: { login: "owner" } }, 9403);
     await upsertRepositorySettings(env, { repoFullName: "owner/agent-repo", autonomy: { merge: "auto" }, gateCheckMode: "enabled", checkRunMode: "off", commentMode: "off", publicSurface: "off" });
-    // PR 1: missing its current Gate check -- the one priority repair.
+    // PR 1: missing its current Gate check -- the one priority repair. Make it newer-by-regate than the
+    // ordinary stale PRs below, reproducing the backlog bug where a max=1 staleness slice could drop the repair.
     await upsertPullRequestFromGitHub(env, "owner/agent-repo", { number: 1, title: "Repair 1", state: "open", user: { login: "c" }, head: { sha: "repair-1" }, labels: [], body: "" });
     await repositoriesModule.markPullRequestSurfacePublished(env, "owner/agent-repo", 1, "repair-1");
+    await env.DB.prepare("update pull_requests set last_regated_at = ? where repo_full_name = ? and number = ?")
+      .bind("2026-05-28T01:59:00.000Z", "owner/agent-repo", 1)
+      .run();
     // PRs 2-5: ordinary, already-current, stale-by-time PRs -- a normal (no-backlog) sweep would pick these up
     // too, but while the backlog is draining they must sit out so the sweep only carries the priority repair.
     for (const number of [2, 3, 4, 5]) {
       const headSha = `stale-${number}`;
       await upsertPullRequestFromGitHub(env, "owner/agent-repo", { number, title: `Stale ${number}`, state: "open", user: { login: "c" }, head: { sha: headSha }, labels: [], body: "" });
       await repositoriesModule.markPullRequestSurfacePublished(env, "owner/agent-repo", number, headSha);
+      await env.DB.prepare("update pull_requests set last_regated_at = ? where repo_full_name = ? and number = ?")
+        .bind(`2026-05-28T01:0${number}:00.000Z`, "owner/agent-repo", number)
+        .run();
       await upsertCheckSummary(env, {
         id: `gate-current-${number}`,
         repoFullName: "owner/agent-repo",