diff --git a/unit_test/dependency_constraints_test.py b/unit_test/dependency_constraints_test.py
index 5d38cabb..b3fb0cb3 100644
--- a/unit_test/dependency_constraints_test.py
+++ b/unit_test/dependency_constraints_test.py
@@ -16,6 +16,14 @@ def test_defaults():
         dependency_constraints.get_for_python_version('3.8'),
         os.path.join(resources_dir, 'constraints.txt')
     )
+    assert os.path.samefile(
+        dependency_constraints.get_for_python_version('3.6'),
+        os.path.join(resources_dir, 'constraints-python36.txt')
+    )
+    assert os.path.samefile(
+        dependency_constraints.get_for_python_version('3.5'),
+        os.path.join(resources_dir, 'constraints-python35.txt')
+    )
     assert os.path.samefile(
         dependency_constraints.get_for_python_version('2.7'),
         os.path.join(resources_dir, 'constraints-python27.txt')