diff --git a/src/taskgraph/config.py b/src/taskgraph/config.py
index b914b98f..52018846 100644
--- a/src/taskgraph/config.py
+++ b/src/taskgraph/config.py
@@ -145,7 +145,7 @@ def vcs_root(self):
             raise Exception(
                 "Not guessing path to vcs root. Graph config in non-standard location."
             )
-        return os.path.dirname(self.root_dir)
+        return os.path.dirname(os.path.join(".", self.root_dir))
 
     @property
     def taskcluster_yml(self):