diff --git a/src/hdmf_zarr/backend.py b/src/hdmf_zarr/backend.py
index 24954ae6..086c24bf 100644
--- a/src/hdmf_zarr/backend.py
+++ b/src/hdmf_zarr/backend.py
@@ -643,7 +643,7 @@ def resolve_ref(self, zarr_ref):
             source_file = os.path.abspath(os.path.join(self.source, source_file))
         else:
             # get rid of extra "/" and "./" in the path root and source_file
-            root_path = str(self.path).rstrip("/") 
+            root_path = str(self.path).rstrip("/")
             source_path = str(source_file).lstrip(".")
             source_file = os.path.join(root_path, source_path)