diff --git a/datenguidepy/TEST_PROJECT_STRUCTURE b/datenguidepy/TEST_PROJECT_STRUCTURE
new file mode 100644
index 0000000..e69de29
diff --git a/tests/unit_tests/test_project_structure.py b/tests/unit_tests/test_project_structure.py
new file mode 100644
index 0000000..e01d381
--- /dev/null
+++ b/tests/unit_tests/test_project_structure.py
@@ -0,0 +1,25 @@
+import os
+import datenguidepy.query_builder
+
+
+def test_project_structure():
+    """Test package loading in tox.
+
+    The package struture has an issue in combination
+    with tox and pytest. Tox packages and installs an sdist
+    of the package, nevertheless when the tests are executed
+    this installed package is shadowed by the (not installed)
+    version of the package in the project folder. This happens
+    because pytest dynamically adds paths to sys.path
+    to run the test cases. The problem with this is that error
+    in the MANIFEST.in are not caught when modules from the
+    projects folder are used instead of the installd sdist.
+
+    This testcase checks for a file in the module folder of query_builder.
+    This file is NOT in the Manifest.in and should therefore not
+    be found in a tox test.
+    """
+    mod_dir = os.path.dirname(os.path.abspath(datenguidepy.query_builder.__file__))
+    test_file = "TEST_PROJECT_STRUCTURE"
+    test_path = os.path.join(mod_dir, test_file)
+    assert not os.path.isfile(test_path)