diff --git a/src/media/outbound-attachment.test.ts b/src/media/outbound-attachment.test.ts
new file mode 100644
index 00000000000..e5618469b82
--- /dev/null
+++ b/src/media/outbound-attachment.test.ts
@@ -0,0 +1,39 @@
+import { describe, expect, it, vi } from "vitest";
+
+const loadWebMedia = vi.hoisted(() => vi.fn());
+const saveMediaBuffer = vi.hoisted(() => vi.fn());
+
+vi.mock("./web-media.js", () => ({
+  loadWebMedia,
+}));
+
+vi.mock("./store.js", () => ({
+  saveMediaBuffer,
+}));
+
+const { resolveOutboundAttachmentFromUrl } = await import("./outbound-attachment.js");
+
+describe("resolveOutboundAttachmentFromUrl", () => {
+  it("preserves the loaded file name when staging outbound media", async () => {
+    const buffer = Buffer.from("pdf");
+    loadWebMedia.mockResolvedValueOnce({
+      buffer,
+      contentType: "application/pdf",
+      fileName: "report.pdf",
+    });
+    saveMediaBuffer.mockResolvedValueOnce({
+      path: "/tmp/media/outbound/report---uuid.pdf",
+      contentType: "application/pdf",
+    });
+
+    await resolveOutboundAttachmentFromUrl("./report.pdf", 1024);
+
+    expect(saveMediaBuffer).toHaveBeenCalledWith(
+      buffer,
+      "application/pdf",
+      "outbound",
+      1024,
+      "report.pdf",
+    );
+  });
+});
diff --git a/src/media/outbound-attachment.ts b/src/media/outbound-attachment.ts
index ac303b07d74..fa9a93a1b66 100644
--- a/src/media/outbound-attachment.ts
+++ b/src/media/outbound-attachment.ts
@@ -25,6 +25,7 @@ export async function resolveOutboundAttachmentFromUrl(
     media.contentType ?? undefined,
     "outbound",
     maxBytes,
+    media.fileName,
   );
   return { path: saved.path, contentType: saved.contentType };
 }