diff --git a/devgen/modules/diff_builder.py b/devgen/modules/diff_builder.py
index 90cf7dc..02017b7 100644
--- a/devgen/modules/diff_builder.py
+++ b/devgen/modules/diff_builder.py
@@ -128,7 +128,7 @@ class FileGrouper:
             deepest = max(candidates, key=lambda p: len(Path(p).parts))
             parent_path = str(Path(deepest).parent)
             new_key = "root" if parent_path == "." else parent_path
-            groups[new_key].extend(groups.pop(deepest))
+            groups.setdefault(new_key, []).extend(groups.pop(deepest))
         return groups
 
 
diff --git a/pyproject.toml b/pyproject.toml
index 312531b..cd38108 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "devgen-cli"
-version = "0.2.5"
+version = "0.2.6"
 description = "A collection of developer tools"
 readme = "README.md"
 requires-python = ">=3.10"
diff --git a/setup.py b/setup.py
index e6609d8..303fddc 100644
--- a/setup.py
+++ b/setup.py
@@ -6,7 +6,7 @@ from setuptools import find_packages, setup
 
 setup(
     name="devgen-cli",
-    version="0.2.5",
+    version="0.2.6",
     packages=find_packages(),
     include_package_data=True,
     install_requires=[
diff --git a/uv.lock b/uv.lock
index 683bfc6..7bf489f 100644
--- a/uv.lock
+++ b/uv.lock
@@ -180,7 +180,7 @@ wheels = [
 
 [[package]]
 name = "devgen-cli"
-version = "0.2.5"
+version = "0.2.6"
 source = { editable = "." }
 dependencies = [
     { name = "anthropic" },