diff --git a/tests/psf/__init__.py b/tests/psf/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_Zemax.py b/tests/psf/test_Zemax.py
similarity index 100%
rename from tests/test_Zemax.py
rename to tests/psf/test_Zemax.py