Index: wflow-py/wflow/wflow_bmi.py
===================================================================
diff -u -r5b0e933ec18fb26f7f9e84236512d97fa3cc2777 -r04b94635e18ea02ab3ae22351140177d3b8f4c99
--- wflow-py/wflow/wflow_bmi.py	(.../wflow_bmi.py)	(revision 5b0e933ec18fb26f7f9e84236512d97fa3cc2777)
+++ wflow-py/wflow/wflow_bmi.py	(.../wflow_bmi.py)	(revision 04b94635e18ea02ab3ae22351140177d3b8f4c99)
@@ -12,6 +12,7 @@
 class wflowbmi_light(object):
     """
     Deltares specific light version of the BMI. Used for internal model linkage
+    Deltares specific light version of the BMI. Used for internal model linkage
     """
 
     def __init__(self):
@@ -578,7 +579,7 @@
             timespan = time - curtime
             nrsteps = int(timespan/self.dynModel.timestepsecs)
             self.bmilogger.debug('update_until: update timesteps foreward ' + str(nrsteps) + ' to ' + str(curtime))
-            self.dynModel._runDynamic(self.currenttimestep, self.currenttimestep + nrsteps)
+            self.dynModel._runDynamic(self.currenttimestep, self.currenttimestep + nrsteps -1)
             self.currenttimestep = self.currenttimestep + nrsteps
 
     def update_frac(self, time_frac):