diff --git a/packages/git/src/diff.ts b/packages/git/src/diff.ts
index b13a9f2..c7f7191 100644
--- a/packages/git/src/diff.ts
+++ b/packages/git/src/diff.ts
@@ -38,7 +38,11 @@ export function resolveDiffArgs(ref: string): RefDiffArgs {
     case 'work':
       return { type: 'args', args: ['HEAD'], includeUntracked: true };
     default:
-      return { type: 'args', args: [normalizeRef(ref)], includeUntracked: true };
+      // Bare refs (`diffity main`) diff against the working tree, so untracked
+      // files are part of the change set (#10). Ranges (`A..B`) pin both
+      // endpoints — the working tree isn't involved, so untracked files must
+      // be excluded or the diff won't match `git diff A..B`.
+      return { type: 'args', args: [normalizeRef(ref)], includeUntracked: !ref.includes('..') };
   }
 }
 
diff --git a/packages/git/tests/get-diff-files.test.ts b/packages/git/tests/get-diff-files.test.ts
index ec3684d..0b1ad05 100644
--- a/packages/git/tests/get-diff-files.test.ts
+++ b/packages/git/tests/get-diff-files.test.ts
@@ -86,6 +86,28 @@ describe('getDiffFiles', () => {
     git('checkout -- base.txt');
   });
 
+  it('includes untracked files for bare refs (diff against working tree)', async () => {
+    const { getDiffFiles } = await import('../src/diff.js');
+    writeFile('untracked-file.txt', 'untracked\n');
+
+    const files = getDiffFiles('main');
+    expect(files).toContain('untracked-file.txt');
+
+    execSync(`rm "${join(repoDir, 'untracked-file.txt')}"`, { stdio: 'pipe' });
+  });
+
+  it('excludes untracked files for range refs (both endpoints pinned)', async () => {
+    const { getDiffFiles } = await import('../src/diff.js');
+    writeFile('untracked-file.txt', 'untracked\n');
+
+    const files = getDiffFiles('main..feature');
+    expect(files).toContain('feature.txt');
+    expect(files).toContain('base.txt');
+    expect(files).not.toContain('untracked-file.txt');
+
+    execSync(`rm "${join(repoDir, 'untracked-file.txt')}"`, { stdio: 'pipe' });
+  });
+
   it('returns working tree files for work ref', async () => {
     const { getDiffFiles } = await import('../src/diff.js');
     writeFile('untracked-file.txt', 'untracked\n');