diff --git a/backend/__tests__/services/uploadSettingsFileTypes.test.js b/backend/__tests__/services/uploadSettingsFileTypes.test.js
new file mode 100644
index 00000000..13b38736
--- /dev/null
+++ b/backend/__tests__/services/uploadSettingsFileTypes.test.js
@@ -0,0 +1,51 @@
+const fs = require('fs');
+const path = require('path');
+
+const {
+  EXTENSION_TO_MIME,
+  extensionsToMimeTypes,
+} = require('../../src/services/uploadSettings');
+const { validateFileType } = require('../../src/utils/fileSecurityUtils');
+
+const RAW_AND_HEIF_TYPES = {
+  dng: 'image/x-adobe-dng',
+  heic: 'image/heic',
+  heif: 'image/heif',
+};
+
+function getFrontendExtensionMap() {
+  const source = fs.readFileSync(
+    path.join(__dirname, '../../../frontend/src/utils/fileTypes.ts'),
+    'utf8'
+  );
+  const match = source.match(/const EXTENSION_TO_MIME[^=]*= \{([\s\S]*?)\n\};/);
+  if (!match) throw new Error('Could not find frontend EXTENSION_TO_MIME');
+
+  // Parse `key: 'mime',` entries — quoted keys and trailing `//` comments are
+  // tolerated; any other non-blank, non-comment line inside the map is a parse
+  // failure, so a syntax the parser can't read fails loudly instead of silently
+  // dropping the entry from the comparison.
+  const entries = [];
+  for (const line of match[1].split('\n')) {
+    const trimmed = line.trim();
+    if (trimmed === '' || trimmed.startsWith('//')) continue;
+    const entry = trimmed.match(/^'?(\w+)'?\s*:\s*'([^']+)'\s*,?\s*(?:\/\/.*)?$/);
+    if (!entry) throw new Error(`Unparsable EXTENSION_TO_MIME line in frontend fileTypes.ts: "${trimmed}"`);
+    entries.push([entry[1], entry[2]]);
+  }
+  return Object.fromEntries(entries);
+}
+
+describe('configured upload file types', () => {
+  test('supports configured DNG, HEIC, and HEIF uploads', () => {
+    expect(extensionsToMimeTypes('dng,heic,heif')).toEqual(Object.values(RAW_AND_HEIF_TYPES));
+
+    for (const [extension, mimeType] of Object.entries(RAW_AND_HEIF_TYPES)) {
+      expect(validateFileType(`image.${extension}`, mimeType, [mimeType])).toBe(true);
+    }
+  });
+
+  test('uses the same extension-to-MIME map as the frontend', () => {
+    expect(getFrontendExtensionMap()).toEqual(EXTENSION_TO_MIME);
+  });
+});