diff --git a/test/test.py b/test/test.py
index c8eb588c..78786d84 100644
--- a/test/test.py
+++ b/test/test.py
@@ -156,7 +156,7 @@ class TestBase():
         """
 
         checkout = TestBase.locate_test_checkout()
-        output = subprocess.check_output([os.path.join(checkout, "tree-diff"), path1, path2])
+        output = subprocess.check_output([os.path.join(checkout, "tools/tree-diff"), path1, path2])
         return json.loads(output)
 
 
diff --git a/tree-diff b/tools/tree-diff
similarity index 100%
rename from tree-diff
rename to tools/tree-diff