diff --git a/trick_sims/Cannon/SIM_cannon_numeric/RUN_test/input.py b/trick_sims/Cannon/SIM_cannon_numeric/RUN_test/input.py
index e9b5b324..69198ba1 100644
--- a/trick_sims/Cannon/SIM_cannon_numeric/RUN_test/input.py
+++ b/trick_sims/Cannon/SIM_cannon_numeric/RUN_test/input.py
@@ -1,6 +1,5 @@
 
-#execfile("Modified_data/realtime.py")
+execfile("Modified_data/realtime.py")
 execfile("Modified_data/cannon.dr")
 
-dyn_integloop.getIntegrator(trick.Runge_Kutta_4, 4)
-trick.exec_set_terminate_time(5.2)
+dyn_integloop.getIntegrator(trick.Runge_Kutta_4, 5)
diff --git a/trick_sims/Cannon/SIM_cannon_numeric/RUN_test/unit_test.py b/trick_sims/Cannon/SIM_cannon_numeric/RUN_test/unit_test.py
index 29455032..9db27413 100644
--- a/trick_sims/Cannon/SIM_cannon_numeric/RUN_test/unit_test.py
+++ b/trick_sims/Cannon/SIM_cannon_numeric/RUN_test/unit_test.py
@@ -1,3 +1,3 @@
 
-dyn_integloop.getIntegrator(trick.Runge_Kutta_4, 4)
+dyn_integloop.getIntegrator(trick.Runge_Kutta_4, 5)
 trick.exec_set_terminate_time(5.2)
diff --git a/trick_sims/Cannon/SIM_cannon_numeric/S_define b/trick_sims/Cannon/SIM_cannon_numeric/S_define
index e16d9d31..09a892db 100644
--- a/trick_sims/Cannon/SIM_cannon_numeric/S_define
+++ b/trick_sims/Cannon/SIM_cannon_numeric/S_define
@@ -5,7 +5,7 @@ LIBRARY DEPENDENCIES:
     (
      (cannon/gravity/src/cannon_default_data.c)
      (cannon/gravity/src/cannon_init.c)
-     (cannon/gravity/src/cannon_deriv_impact.c)
+     (cannon/gravity/src/cannon_deriv.c)
      (cannon/gravity/src/cannon_integ.c)
      (cannon/gravity/src/cannon_impact.c)
     )
@@ -26,7 +26,7 @@ class CannonSimObject : public Trick::SimObject {
 
             ("initialization") cannon_init( &cannon ) ;
 
-            ("derivative") cannon_deriv_impact( &cannon ) ;
+            ("derivative") cannon_deriv( &cannon ) ;
             ("integration") trick_ret = cannon_integ( &cannon ) ;
 
             ("dynamic_event") cannon_impact( &cannon) ;