diff --git a/README.md b/README.md
index c5f869d52..4a30345a2 100644
--- a/README.md
+++ b/README.md
@@ -157,5 +157,15 @@ post_hooks:
    - "black ."
 ```
 
+### protected_dirs
+
+Specify directories to preserve when updating the client.
+
+```yaml
+protected_dirs:
+   - "util"
+   - "cli" 
+```
+
 [changelog.md]: CHANGELOG.md
 [poetry]: https://python-poetry.org/
diff --git a/openapi_python_client/__init__.py b/openapi_python_client/__init__.py
index 978b3d8df..afb0b794a 100644
--- a/openapi_python_client/__init__.py
+++ b/openapi_python_client/__init__.py
@@ -2,6 +2,7 @@
 
 import json
 import mimetypes
+import os
 import shutil
 import subprocess
 import sys
@@ -127,7 +128,21 @@ def update(self) -> Sequence[GeneratorError]:
         if not self.package_dir.is_dir():
             return [GeneratorError(detail=f"Directory {self.package_dir} not found")]
         print(f"Updating {self.package_name}")
-        shutil.rmtree(self.package_dir)
+
+        if not self.config.protected_dirs:
+            shutil.rmtree(self.package_dir)
+        else:
+            files_and_dirs: List[str] = os.listdir(self.package_dir)
+            for protected_dir in self.config.protected_dirs:
+                files_and_dirs.remove(protected_dir)
+
+            for file_or_dir in files_and_dirs:
+                path = os.path.join(self.package_dir, file_or_dir)
+                if os.path.isfile(path):
+                    os.remove(path)
+                if os.path.isdir(path):
+                    shutil.rmtree(path)
+
         self._create_package()
         self._build_models()
         self._build_api()
@@ -170,7 +185,7 @@ def _get_errors(self) -> List[GeneratorError]:
         return errors
 
     def _create_package(self) -> None:
-        self.package_dir.mkdir()
+        self.package_dir.mkdir(exist_ok=True)
         # Package __init__.py
         package_init = self.package_dir / "__init__.py"
 
diff --git a/openapi_python_client/config.py b/openapi_python_client/config.py
index ace95c6b1..116d2bb09 100644
--- a/openapi_python_client/config.py
+++ b/openapi_python_client/config.py
@@ -27,6 +27,7 @@ class Config(BaseModel):
     project_name_override: Optional[str]
     package_name_override: Optional[str]
     package_version_override: Optional[str]
+    protected_dirs: Optional[List[str]]
     post_hooks: List[str] = [
         "autoflake -i -r --remove-all-unused-imports --remove-unused-variables --ignore-init-module-imports .",
         "isort .",