diff --git a/opencsp/app/sofast/SofastGUI.py b/opencsp/app/sofast/SofastGUI.py
index 2b1f8b74d..007ce9094 100644
--- a/opencsp/app/sofast/SofastGUI.py
+++ b/opencsp/app/sofast/SofastGUI.py
@@ -32,7 +32,7 @@ def __init__(self) -> 'SofastGUI':
         Instantiates GUI in new window
         """
         # Create the service object
-        self.service = SofastService()
+        self.service = SofastService(self)
 
         # Create tkinter object
         self.root = tkinter.Tk()