diff --git a/ssapy/plotUtils.py b/ssapy/plotUtils.py
index 6360a07..6b4279c 100644
--- a/ssapy/plotUtils.py
+++ b/ssapy/plotUtils.py
@@ -22,6 +22,8 @@
 from PIL import Image as PILImage
 import ipyvolume as ipv
 
+from typing import Union
+
 
 def load_earth_file():
     earth = PILImage.open(find_file("earth", ext=".png"))