diff --git a/flopy/mf6/data/mfstructure.py b/flopy/mf6/data/mfstructure.py
index 4446210306..3b1b58c1b5 100644
--- a/flopy/mf6/data/mfstructure.py
+++ b/flopy/mf6/data/mfstructure.py
@@ -92,6 +92,8 @@ def __init__(self):
             "utlobs": 0,
             "utlts": 0,
             "utltas": 0,
+            "utlspc": 0,
+            "utlspca": 0,
         }
 
     def get_file_list(self):