diff --git a/csst_mci_sim/csst_mci_sim.py b/csst_mci_sim/csst_mci_sim.py
index 69438a675e971df377959ae98472bb64068ab29b..390706ba3825b39561d2a9fd6eb26fbf504b327d 100644
--- a/csst_mci_sim/csst_mci_sim.py
+++ b/csst_mci_sim/csst_mci_sim.py
@@ -1487,7 +1487,7 @@ class MCIsimulator():
         Configures the simulator with input information and creates and empty array to which the final image will
         be build on.
         """
-        self.readConfigs(simnumber,source)
+        self.readConfigs(simnumber,sourcein)
         
         self.processConfigs()