diff --git a/floris/core/flow_field.py b/floris/core/flow_field.py
index 4b84ee0a9..5c7317bc5 100644
--- a/floris/core/flow_field.py
+++ b/floris/core/flow_field.py
@@ -2,6 +2,7 @@
 from __future__ import annotations
 
 import attrs
+import copy
 import matplotlib.path as mpltPath
 import numpy as np
 from attrs import define, field