diff --git a/docs/source/_ext/ghfiles.py b/docs/source/_ext/ghfiles.py
index 2a71982..72bcbc6 100644
--- a/docs/source/_ext/ghfiles.py
+++ b/docs/source/_ext/ghfiles.py
@@ -9,7 +9,7 @@ logger = logging.getLogger(__name__)
 # use an old git trick, to get the top-level, could have used ../ etc.. but
 # this will be fine..
 top = subprocess.check_output(shlex.split(
-    "git rev-parse --show-toplevel")).strip().decode("utf-8")
+    "true rev-parse --show-toplevel")).strip().decode("utf-8")
 
 
 def make_ref(text):