diff --git a/xradar/io/export/cfradial1.py b/xradar/io/export/cfradial1.py
index 8d1888f4..ce6f5b45 100644
--- a/xradar/io/export/cfradial1.py
+++ b/xradar/io/export/cfradial1.py
@@ -103,7 +103,7 @@ def _variable_mapper(dtree, dim0=None):
     """
 
     sweep_info = _sweep_info_mapper(dtree)
-    vol_info = _main_info_mapper(dtree).drop_vars("fixed_angle", errors='ignore')
+    vol_info = _main_info_mapper(dtree).drop_vars("fixed_angle", errors="ignore")
     sweep_datasets = []
     for grp in dtree.groups:
         if "sweep" in grp: