diff --git a/test/test_api/test_project.py b/test/test_api/test_project.py
index c8533618..9ca4686c 100644
--- a/test/test_api/test_project.py
+++ b/test/test_api/test_project.py
@@ -6,6 +6,7 @@ import pytest
 from ..helpers import get_example_dir, set_cwd, root_dir, test_dir
 from jedi import Interpreter
 from jedi.api import Project, get_default_project
+from jedi.api.project import _is_potential_project, _CONTAINS_POTENTIAL_PROJECT
 
 
 def test_django_default_project(Script):
@@ -160,3 +161,21 @@ def test_complete_search(Script, string, completions, all_scopes):
     project = Project(test_dir)
     defs = project.complete_search(string, all_scopes=all_scopes)
     assert [d.complete for d in defs] == completions
+
+
+@pytest.mark.parametrize(
+    'path,expected', [
+        (Path(__file__).parents[2], True), # The path of the project
+        (Path(__file__).parents[1], False), # The path of the tests, not a project
+        (Path.home(), None)
+    ]
+)
+def test_is_potential_project(path, expected):
+
+    if expected is None:
+        try:
+            expected = _CONTAINS_POTENTIAL_PROJECT in os.listdir(path)
+        except OSError:
+            expected = False
+
+    assert _is_potential_project(path) == expected
diff --git a/test/test_inference/test_sys_path.py b/test/test_inference/test_sys_path.py
index 2fa0e4df..d22cc2e0 100644
--- a/test/test_inference/test_sys_path.py
+++ b/test/test_inference/test_sys_path.py
@@ -108,3 +108,13 @@ def test_transform_path_to_dotted(sys_path_, module_path, expected, is_package):
     module_path = os.path.abspath(module_path)
     assert sys_path.transform_path_to_dotted(sys_path_, Path(module_path)) \
         == (expected, is_package)
+
+
+@pytest.mark.parametrize(
+    'path,filename,expected', [
+        (Path(__file__).parents[1], "setup.py", Path(__file__).parents[2]),
+        (Path(__file__).parents[2], os.path.basename(__file__), None)
+    ]
+)
+def test_get_parent_dir_with_file(path, filename, expected):
+    assert sys_path._get_parent_dir_with_file(path, filename) == expected