diff --git a/{{ cookiecutter.format }}/src/sitecustomize.py b/{{ cookiecutter.format }}/src/sitecustomize.py
new file mode 100644
index 0000000..a8e8e75
--- /dev/null
+++ b/{{ cookiecutter.format }}/src/sitecustomize.py	
@@ -0,0 +1,18 @@
+# A site customization that processes .pth files from "app_packages".
+import os
+import sys
+import site
+
+# Add the "app_packages" directory to the path and process its .pth files.
+site.addsitedir(os.path.join(os.path.dirname(__file__), "app_packages"))
+
+# Call the next sitecustomize script if there is one
+# (https://nedbatchelder.com/blog/201001/running_code_at_python_startup.html).
+del sys.modules["sitecustomize"]
+this_dir = os.path.dirname(__file__)
+path_index = sys.path.index(this_dir)
+del sys.path[path_index]
+try:
+    import sitecustomize  # noqa: F401
+finally:
+    sys.path.insert(path_index, this_dir)
\ No newline at end of file