diff --git a/src/web/routes/file-routes.ts b/src/web/routes/file-routes.ts
index adffc9dd..9cad66cf 100644
--- a/src/web/routes/file-routes.ts
+++ b/src/web/routes/file-routes.ts
@@ -571,8 +571,21 @@ async function resolveFilesystemPickerPath(
     throwFilesystemPickerError(403, ApiErrorCode.INVALID_INPUT, 'No filesystem browse roots are available');
   }
 
+  // With no explicit path (the "Link Existing" case picker, which passes no
+  // sessionId and an empty initialPath until the user has typed something),
+  // land on the shared cases root rather than falling through to whichever
+  // root happens to be first. `Home` is only nested under `Codeman Cases` on
+  // the native default (~/codeman-cases); a Docker deployment binds them at
+  // unrelated host paths (CODEMAN_APPDATA_PATH vs CODEMAN_CASES_PATH), so a
+  // Home-first fallback opened the picker somewhere with no cases in sight —
+  // and, worse, made an OLD case folder left behind by a since-changed
+  // CODEMAN_CASES_PATH look like a normal thing to stumble across while
+  // browsing for one to link.
   const fallbackRoot =
-    roots.find((root) => root.label === 'Current Folder') ?? roots.find((root) => root.path === '/mnt/d') ?? roots[0];
+    roots.find((root) => root.label === 'Current Folder') ??
+    roots.find((root) => root.label === 'Codeman Cases') ??
+    roots.find((root) => root.path === '/mnt/d') ??
+    roots[0];
   const candidatePath = resolve(requestedPath ?? fallbackRoot.path);
 
   let resolvedPath: string;
diff --git a/test/routes/file-routes.test.ts b/test/routes/file-routes.test.ts
index 9552c32a..e8c532d3 100644
--- a/test/routes/file-routes.test.ts
+++ b/test/routes/file-routes.test.ts
@@ -10,6 +10,7 @@ import { Readable } from 'node:stream';
 import { createRouteTestHarness, type RouteTestHarness } from './_route-test-utils.js';
 import { registerFileRoutes } from '../../src/web/routes/file-routes.js';
 import { ApiErrorCode } from '../../src/types.js';
+import { CASES_DIR } from '../../src/web/route-helpers.js';
 
 // Mock fs/promises for file operations
 vi.mock('node:fs/promises', () => ({
@@ -114,6 +115,20 @@ describe('file-routes', () => {
       ]);
     });
 
+    it('defaults to the Codeman Cases root, not Home, when linking a case with no path chosen yet', async () => {
+      // The "Link Existing" case picker opens with an empty path and no
+      // sessionId. `Home` and `Codeman Cases` are unrelated bind mounts under
+      // Docker, so falling back to whichever root happened to be listed first
+      // could open the picker somewhere with no cases in it at all — and, worse,
+      // make a stale directory from a since-changed CODEMAN_CASES_PATH look like
+      // a normal thing to stumble across while browsing for one to link.
+      const res = await harness.app.inject({ method: 'GET', url: '/api/filesystem/browse' });
+
+      expect(res.statusCode).toBe(200);
+      const body = JSON.parse(res.body);
+      expect(body.data.path).toBe(CASES_DIR);
+    });
+
     it('rejects paths outside the configured roots', async () => {
       const res = await harness.app.inject({
         method: 'GET',