diff --git a/lisainstrument/instrument.py b/lisainstrument/instrument.py
index cbac025d3f5265770a27a1915bc65f7605e37b1a..3a5209af15c3a0d12ec5ded9c750e90d390b2887 100755
--- a/lisainstrument/instrument.py
+++ b/lisainstrument/instrument.py
@@ -903,7 +903,7 @@ class Instrument:
         self.simulate_noises()
 
         logger.debug("Computing local timer deviations")
-        t = self.physics_t_withinitial
+        t = self.physics_et_withinitial
 
         self.the_wrt_tcb_local_withinitial = \
             self.tps_wrt_tcb \