diff --git a/impedance/models/circuits/fitting.py b/impedance/models/circuits/fitting.py
index 5fe1c30..a37de37 100644
--- a/impedance/models/circuits/fitting.py
+++ b/impedance/models/circuits/fitting.py
@@ -324,6 +324,8 @@ def count_parens(string):
         split = parallel
     elif series == parallel:  # only single element
         split = series
+    else:
+        split = parallel
 
     for i, elem in enumerate(split):
         if ',' in elem or '-' in elem: