diff --git a/trick_sims/SIM_balloon/RUN_test/input.py b/trick_sims/SIM_balloon/RUN_test/input.py
index ca461654..b186984d 100644
--- a/trick_sims/SIM_balloon/RUN_test/input.py
+++ b/trick_sims/SIM_balloon/RUN_test/input.py
@@ -1,4 +1,4 @@
-execfile("Modified_data/realtime.py")
+exec(open("./Modified_data/realtime.py").read())
 
 dyn.balloon.pos[0] = 0
 #dyn.balloon.pos[1] = 136.89
diff --git a/trick_sims/SIM_contact/RUN_Newtons_cradle/input.py b/trick_sims/SIM_contact/RUN_Newtons_cradle/input.py
index 734704dc..bf2b5302 100644
--- a/trick_sims/SIM_contact/RUN_Newtons_cradle/input.py
+++ b/trick_sims/SIM_contact/RUN_Newtons_cradle/input.py
@@ -1,4 +1,4 @@
-execfile("Modified_data/realtime.py")
+exec(open("./Modified_data/realtime.py").read())
 
 # Variable Server Data should be copied at top of frame.
 trick.var_set_copy_mode(2)
diff --git a/trick_sims/SIM_contact/RUN_ball_line/input.py b/trick_sims/SIM_contact/RUN_ball_line/input.py
index bb9ffdbb..202729f9 100644
--- a/trick_sims/SIM_contact/RUN_ball_line/input.py
+++ b/trick_sims/SIM_contact/RUN_ball_line/input.py
@@ -1,4 +1,4 @@
-execfile("Modified_data/realtime.py")
+exec(open("./Modified_data/realtime.py").read())
 
 # Variable Server Data should be copied at top of frame.
 trick.var_set_copy_mode(2)
diff --git a/trick_sims/SIM_contact/RUN_multi_collision/input.py b/trick_sims/SIM_contact/RUN_multi_collision/input.py
index c025cb7b..a969b177 100644
--- a/trick_sims/SIM_contact/RUN_multi_collision/input.py
+++ b/trick_sims/SIM_contact/RUN_multi_collision/input.py
@@ -1,4 +1,4 @@
-execfile("Modified_data/realtime.py")
+exec(open("./Modified_data/realtime.py").read())
 
 # Variable Server Data should be copied at top of frame.
 trick.var_set_copy_mode(2)
diff --git a/trick_sims/SIM_contact/RUN_pool_break/input.py b/trick_sims/SIM_contact/RUN_pool_break/input.py
index f3db9095..9284fa6c 100644
--- a/trick_sims/SIM_contact/RUN_pool_break/input.py
+++ b/trick_sims/SIM_contact/RUN_pool_break/input.py
@@ -1,4 +1,4 @@
-execfile("Modified_data/realtime.py")
+exec(open("./Modified_data/realtime.py").read())
 
 # Variable Server Data should be copied at top of frame.
 trick.var_set_copy_mode(2)
diff --git a/trick_sims/SIM_contact/RUN_simple_collision/input.py b/trick_sims/SIM_contact/RUN_simple_collision/input.py
index 9cd6de2e..0ef149e9 100644
--- a/trick_sims/SIM_contact/RUN_simple_collision/input.py
+++ b/trick_sims/SIM_contact/RUN_simple_collision/input.py
@@ -1,4 +1,4 @@
-execfile("Modified_data/realtime.py")
+exec(open("./Modified_data/realtime.py").read())
 
 # Variable Server Data should be copied at top of frame.
 trick.var_set_copy_mode(2)
diff --git a/trick_sims/SIM_contact/RUN_test5/input.py b/trick_sims/SIM_contact/RUN_test5/input.py
index e7120a96..7c36452e 100644
--- a/trick_sims/SIM_contact/RUN_test5/input.py
+++ b/trick_sims/SIM_contact/RUN_test5/input.py
@@ -1,4 +1,4 @@
-execfile("Modified_data/realtime.py")
+exec(open("./Modified_data/realtime.py").read())
 
 # Variable Server Data should be copied at top of frame.
 trick.var_set_copy_mode(2)
diff --git a/trick_sims/SIM_lander/RUN_test/input.py b/trick_sims/SIM_lander/RUN_test/input.py
index 9eae0188..d78545e1 100644
--- a/trick_sims/SIM_lander/RUN_test/input.py
+++ b/trick_sims/SIM_lander/RUN_test/input.py
@@ -1,4 +1,4 @@
-execfile("Modified_data/realtime.py")
+exec(open("./Modified_data/realtime.py").read())
 
 dyn.lander.pos[0] = 0
 dyn.lander.pos[1] = 1.8