diff --git a/sandbox_fs_test.py b/sandbox_fs_test.py
index 8b97b98..884ad81 100755
--- a/sandbox_fs_test.py
+++ b/sandbox_fs_test.py
@@ -11,6 +11,7 @@ import unittest
 
 
 tempfile.tempdir = os.getcwd()  # This tests fails when using /tmp.
+VIGIL_ROOT = os.path.dirname(__file__)
 
 
 def _get_test_paths(temp_dir):
@@ -26,7 +27,8 @@ class SandboxFilesystemTestCase(unittest.TestCase):
         with tempfile.TemporaryDirectory() as temp_dir:
             a_dir, foo_path, bar_path = _get_test_paths(temp_dir)
             os.mkdir(a_dir)
-            subprocess.check_call(["./sandbox_fs", a_dir, "--", __file__,
+            sandbox_fs_path = os.path.join(VIGIL_ROOT, "sandbox_fs")
+            subprocess.check_call([sandbox_fs_path, a_dir, "--", __file__,
                                    temp_dir])
             self.assertTrue(os.path.exists(foo_path))
             self.assertFalse(os.path.exists(bar_path))
diff --git a/tools_test.py b/tools_test.py
index 9746c86..3bf0437 100755
--- a/tools_test.py
+++ b/tools_test.py
@@ -41,7 +41,7 @@ def result_path(tool, input_filename):
 
 
 def run_tool(tool, input_filename):
-    with chdir("golden-files"):
+    with chdir(os.path.join(VIGIL_ROOT, "golden-files")):
         return tool(os.path.join(".", "input", input_filename))