diff --git a/apps/server/src/routes/shift.ts b/apps/server/src/routes/shift.ts
index 9b0c428..194bc90 100644
--- a/apps/server/src/routes/shift.ts
+++ b/apps/server/src/routes/shift.ts
@@ -63,7 +63,10 @@ export async function shiftRoutes(app: FastifyInstance, shift: ShiftService): Pr
     const from = canSeeAll ? q.from?.trim() || undefined : undefined;
     const to = canSeeAll ? q.to?.trim() || undefined : undefined;
     const shifts = shift.listShifts({ operator, from, to });
-    return { shifts, scope: canSeeAll ? "all" : "self" };
+    // Admins also get the distinct operator list (unfiltered) for the filter
+    // dropdown — operators don't see other names, so it's scope-gated.
+    if (canSeeAll) return { shifts, scope: "all", operators: shift.listOperators() };
+    return { shifts, scope: "self" };
   });
 
   // NB: drawer cash movements (record/review) moved to routes/drawer.ts (2026-07-01) — the
diff --git a/apps/server/src/shift-service.test.ts b/apps/server/src/shift-service.test.ts
index ca285b1..c57da65 100644
--- a/apps/server/src/shift-service.test.ts
+++ b/apps/server/src/shift-service.test.ts
@@ -234,4 +234,11 @@ describe("close signs a Z-report; listShifts reads it back", () => {
     await shift.open("bob"); await shift.close("bob");
     expect(shift.listShifts({ operator: "alice" }).map((s) => s.operator)).toEqual(["alice"]);
   });
+
+  it("listOperators: distinct + sorted, includes the OPEN shift's operator", async () => {
+    await shift.open("bob"); await shift.close("bob");
+    await shift.open("bob"); await shift.close("bob"); // twice — must stay distinct
+    await shift.open("alice"); // open, no z-report yet
+    expect(shift.listOperators()).toEqual(["alice", "bob"]);
+  });
 });
diff --git a/apps/server/src/shift-service.ts b/apps/server/src/shift-service.ts
index dde17f3..246cfb5 100644
--- a/apps/server/src/shift-service.ts
+++ b/apps/server/src/shift-service.ts
@@ -177,6 +177,28 @@ export class ShiftService {
    * The open shift (no z_report yet) is intentionally excluded — it's not a
    * completed accountability period. Use `currentOpenShift()` for the live one.
    */
+  /**
+   * Every operator that HAS a shift (closed z_reports + the open one, if any),
+   * distinct + sorted — feeds the admin filter dropdown so it can only ever ask
+   * for an operator that exists (the filter is an exact username match).
+   */
+  listOperators(): string[] {
+    const rows = this.#db
+      .select()
+      .from(ledgerEvents)
+      .where(eq(ledgerEvents.type, "shift_z_report"))
+      .all();
+    const names = new Set<string>();
+    for (const r of rows) {
+      const op = ((r.payload ?? {}) as { operator?: string }).operator ?? r.identity;
+      if (op) names.add(op);
+    }
+    const open = this.currentOpenShift();
+    const openOp = open ? (((open.payload ?? {}) as { operator?: string }).operator ?? open.identity) : null;
+    if (openOp) names.add(openOp);
+    return [...names].sort((a, b) => a.localeCompare(b));
+  }
+
   listShifts(opts: { operator?: string; from?: string; to?: string } = {}): ShiftSummary[] {
     const rows = this.#db
       .select()
diff --git a/apps/web/src/ShiftsHistory.tsx b/apps/web/src/ShiftsHistory.tsx
index 81828c3..e66a4a4 100644
--- a/apps/web/src/ShiftsHistory.tsx
+++ b/apps/web/src/ShiftsHistory.tsx
@@ -1,6 +1,6 @@
 import { useEffect, useState } from "react";
 import { useTranslation } from "react-i18next";
-import { useQuery } from "@tanstack/react-query";
+import { keepPreviousData, useQuery } from "@tanstack/react-query";
 import {
   closeShift,
   fetchEvents,
@@ -105,9 +105,17 @@ export function ShiftsHistory({ user, canManage = false }: { user: SessionUser |
     to: range?.to ? new Date(`${range.to}T23:59:59`).toISOString() : undefined,
   };
 
-  const q = useQuery({ queryKey: ["shifts", applied], queryFn: () => fetchShifts(applied) });
+  // keepPreviousData: every filter change makes a NEW query key; without it the
+  // data (and with it `scope`) goes undefined for the fetch round-trip, which
+  // unmounted the admin filter controls mid-interaction and blanked the list.
+  const q = useQuery({
+    queryKey: ["shifts", applied],
+    queryFn: () => fetchShifts(applied),
+    placeholderData: keepPreviousData,
+  });
   const isAdmin = q.data?.scope === "all";
   const closed = q.data?.shifts ?? [];
+  const operators = q.data?.operators ?? [];
 
   // The current/open shift sits at the TOP of the list (when present + visible to me).
   const list: (ShiftSummary & { open?: boolean })[] = current && (isMine || isAdmin) ? [current, ...closed] : closed;
@@ -169,7 +177,14 @@ export function ShiftsHistory({ user, canManage = false }: { user: SessionUser |
         {isAdmin && (
           <div className="field">
             <span className="label">{t("shifts.operator")}</span>
-            <input className="input w-44" value={operator} onChange={(e) => setOperator(e.target.value)} placeholder={t("shifts.allOperators")} />
+            {/* A select over operators that HAVE shifts — the server filter is an
+                exact username match, so free text could only miss. */}
+            <select className="input w-44" value={operator} onChange={(e) => setOperator(e.target.value)}>
+              <option value="">{t("shifts.allOperators")}</option>
+              {operators.map((op) => (
+                <option key={op} value={op}>{op}</option>
+              ))}
+            </select>
           </div>
         )}
       </div>
diff --git a/apps/web/src/api.ts b/apps/web/src/api.ts
index 5e36d46..0037c1e 100644
--- a/apps/web/src/api.ts
+++ b/apps/web/src/api.ts
@@ -1151,6 +1151,8 @@ export interface ShiftSummary extends ShiftSourceSplit {
 export function fetchShifts(params: { operator?: string; from?: string; to?: string } = {}): Promise<{
   shifts: ShiftSummary[];
   scope: "all" | "self";
+  /** Admin scope only: every operator that has a shift — feeds the filter dropdown. */
+  operators?: string[];
 }> {
   const qs = new URLSearchParams();
   if (params.operator) qs.set("operator", params.operator);