diff --git a/src/domain/work-orders/mappers/work-order-board-detail-mapper.ts b/src/domain/work-orders/mappers/work-order-board-detail-mapper.ts
index 144f5e3f..54b333ed 100644
--- a/src/domain/work-orders/mappers/work-order-board-detail-mapper.ts
+++ b/src/domain/work-orders/mappers/work-order-board-detail-mapper.ts
@@ -6,10 +6,7 @@ import type {
   WorkOrderBoardMediaItem,
 } from "@/domain/work-orders/types/work-order-board-detail";
 import { BOARD_MEDIA_CATEGORY_API } from "@/domain/work-orders/types/work-order-board-detail";
-import type {
-  CompletionDocStatus,
-  WorkOrderTableRow,
-} from "@/domain/work-orders/types/work-order-table-row";
+import type { CompletionDocStatus } from "@/domain/work-orders/types/work-order-table-row";
 import type {
   WorkOrderAuditEntry,
   WorkOrderComment,
@@ -273,21 +270,17 @@ export function boardMediaItemsToMediaFiles(items: WorkOrderBoardMediaItem[]): M
 }
 
 /**
- * `GET workorders/{id}/detail` info omits the board row's `MediaCount`, so the table-row mapper
- * defaults it to 0 and the slide-over closability gate would report "At least 1 photo" even
- * after an upload. Keep an explicit count when present; otherwise count the same
- * set the board counts — stored (non-legacy) attachments.
+ * `GET workorders/{id}/detail` info serializes the board row's `MediaCount` as 0 — the detail
+ * DTO inherits the field but the service never sets it — so trusting it verbatim would leave the
+ * slide-over closability gate reporting "At least 1 photo" even after an upload. Take the larger
+ * of the reported count and the stored (non-legacy) attachments: a positive API count still wins,
+ * but a spurious (or omitted) 0 can no longer mask media that are actually present.
  */
-function resolveDetailMediaCount(
-  infoRaw: unknown,
-  info: WorkOrderTableRow,
-  media: WorkOrderBoardMediaItem[],
-): number {
+function resolveDetailMediaCount(infoRaw: unknown, media: WorkOrderBoardMediaItem[]): number {
   const record = asRecord(infoRaw);
-  if (typeof (record.mediaCount ?? record.MediaCount) === "number") {
-    return info.mediaCount;
-  }
-  return media.filter((item) => !item.isLegacy).length;
+  const explicit = record.mediaCount ?? record.MediaCount;
+  const nonLegacyCount = media.filter((item) => !item.isLegacy).length;
+  return Math.max(typeof explicit === "number" ? explicit : 0, nonLegacyCount);
 }
 
 export function mapWorkOrderBoardDetail(raw: unknown): WorkOrderBoardDetail {
@@ -307,7 +300,7 @@ export function mapWorkOrderBoardDetail(raw: unknown): WorkOrderBoardDetail {
   const info = mapWorkOrderTableRow(infoRaw);
 
   return {
-    info: { ...info, mediaCount: resolveDetailMediaCount(infoRaw, info, media) },
+    info: { ...info, mediaCount: resolveDetailMediaCount(infoRaw, media) },
     completion: mapCompletion(completionRaw ?? {}),
     comments,
     audit,
diff --git a/src/test/domain/work-orders/mappers/work-order-board-detail-mapper.test.ts b/src/test/domain/work-orders/mappers/work-order-board-detail-mapper.test.ts
index b393f716..fb24f6b5 100644
--- a/src/test/domain/work-orders/mappers/work-order-board-detail-mapper.test.ts
+++ b/src/test/domain/work-orders/mappers/work-order-board-detail-mapper.test.ts
@@ -297,6 +297,18 @@ describe("mapWorkOrderBoardDetail media count (SH-339)", () => {
     );
   });
 
+  it("prefers stored media when detail info reports an explicit zero", () => {
+    const detail = mapWorkOrderBoardDetail({
+      ...SAMPLE_DETAIL,
+      info: { ...reactiveInfo, mediaCount: 0 },
+    });
+
+    expect(detail.info.mediaCount).toBe(2);
+    expect(getClosabilityGaps(tableRowToClosabilityInput(detail.info))).not.toContain(
+      "At least 1 photo",
+    );
+  });
+
   it("does not count legacy URL-column media, matching the board row count", () => {
     const detail = mapWorkOrderBoardDetail({
       ...SAMPLE_DETAIL,