diff --git a/ceam_tests/util.py b/ceam_tests/util.py
index <HASH>..<HASH> 100644
--- a/ceam_tests/util.py
+++ b/ceam_tests/util.py
@@ -26,6 +26,7 @@ def setup_simulation(components, population_size = 100, start=datetime(1990, 1, 
     return simulation
 
 def pump_simulation(simulation, time_step_days=30.5, duration=None, iterations=None, year_start=1990):
+    config.set('simulation_parameters', 'time_step', '{}'.format(time_step_days))
     timestep = timedelta(days=time_step_days) 
     start_time = datetime(year_start, 1, 1)
     simulation.current_time = start_time
@@ -33,7 +34,7 @@ def pump_simulation(simulation, time_step_days=30.5, duration=None, iterations=N
 
     def should_stop():
         if duration is not None:
-            if simulation.current_time - start_time >= duration:
+            if simulation.current_time - start_time > duration:
                 return True
         elif iterations is not None:
             if iteration_count >= iterations:
@@ -116,7 +117,7 @@ def generate_test_population(event):
         population['fractional_age'] = randomness.random('test_population_age', population.index) * 100
     population['age'] = population['fractional_age'].astype(int)
 
-    population['age'] = 0
+    population['age'] = 0.0
     population['fractional_age'] = 0
 
     population['sex'] = randomness.choice('test_population_sex', population.index, ['Male', 'Female'])
updated the duration code and made age variable a float