diff --git a/python/lsst/ts/wep/task/cutOutDonutsScienceSensorTask.py b/python/lsst/ts/wep/task/cutOutDonutsScienceSensorTask.py
index 437b4ae5..d14cd140 100644
--- a/python/lsst/ts/wep/task/cutOutDonutsScienceSensorTask.py
+++ b/python/lsst/ts/wep/task/cutOutDonutsScienceSensorTask.py
@@ -183,7 +183,7 @@ def assignExtraIntraIdx(self, focusZVal0, focusZVal1, cameraName):
         """
 
         if cameraName in ["LSSTCam", "LSSTComCam", "LSSTComCamSim"]:
-            if focusZVal0 < 0:
+            if focusZVal0 < focusZVal1:
                 extraExpIdx = 1
                 intraExpIdx = 0
             else: