diff --git a/tracetools_test/test/test_node.py b/tracetools_test/test/test_node.py
index cd25e4a..b2086de 100644
--- a/tracetools_test/test/test_node.py
+++ b/tracetools_test/test/test_node.py
@@ -5,8 +5,8 @@ from tracetools_test.utils import (
     cleanup_trace,
 )
 
+BASE_PATH = '/tmp'
 PKG = 'tracetools_test'
-
 node_creation_events = [
     'ros2:rcl_init',
     'ros2:rcl_node_init',
@@ -16,10 +16,9 @@ class TestNode(unittest.TestCase):
 
     def test_creation(self):
         session_name_prefix = 'session-test-node-creation'
-        base_path = '/tmp'
         test_node = ['test_publisher']
 
-        exit_code, full_path = run_and_trace(base_path, session_name_prefix, node_creation_events, None, PKG, test_node)
+        exit_code, full_path = run_and_trace(BASE_PATH, session_name_prefix, node_creation_events, None, PKG, test_node)
         self.assertEqual(exit_code, 0)
 
         trace_events = get_trace_event_names(full_path)
diff --git a/tracetools_test/test/test_publisher.py b/tracetools_test/test/test_publisher.py
index e2ce3d0..ea7da55 100644
--- a/tracetools_test/test/test_publisher.py
+++ b/tracetools_test/test/test_publisher.py
@@ -5,8 +5,8 @@ from tracetools_test.utils import (
     cleanup_trace,
 )
 
+BASE_PATH = '/tmp'
 PKG = 'tracetools_test'
-
 publisher_creation_events = [
     'ros2:rcl_publisher_init',
 ]
@@ -15,10 +15,9 @@ class TestPublisher(unittest.TestCase):
 
     def test_creation(self):
         session_name_prefix = 'session-test-publisher-creation'
-        base_path = '/tmp'
         test_node = ['test_publisher']
 
-        exit_code, full_path = run_and_trace(base_path, session_name_prefix, publisher_creation_events, None, PKG, test_node)
+        exit_code, full_path = run_and_trace(BASE_PATH, session_name_prefix, publisher_creation_events, None, PKG, test_node)
         self.assertEqual(exit_code, 0)
 
         trace_events = get_trace_event_names(full_path)
diff --git a/tracetools_test/test/test_subscription.py b/tracetools_test/test/test_subscription.py
index 5d9e99f..09e63fb 100644
--- a/tracetools_test/test/test_subscription.py
+++ b/tracetools_test/test/test_subscription.py
@@ -5,8 +5,8 @@ from tracetools_test.utils import (
     cleanup_trace,
 )
 
+BASE_PATH = '/tmp'
 PKG = 'tracetools_test'
-
 subscription_creation_events = [
     'ros2:rcl_subscription_init',
     'ros2:rclcpp_subscription_callback_added',
@@ -16,10 +16,9 @@ class TestSubscription(unittest.TestCase):
 
     def test_creation(self):
         session_name_prefix = 'session-test-subscription-creation'
-        base_path = '/tmp'
         test_node = ['test_subscription']
 
-        exit_code, full_path = run_and_trace(base_path, session_name_prefix, subscription_creation_events, None, PKG, test_node)
+        exit_code, full_path = run_and_trace(BASE_PATH, session_name_prefix, subscription_creation_events, None, PKG, test_node)
         self.assertEqual(exit_code, 0)
 
         trace_events = get_trace_event_names(full_path)
diff --git a/tracetools_test/test/test_subscription_callback.py b/tracetools_test/test/test_subscription_callback.py
index c86b58a..cdd5b94 100644
--- a/tracetools_test/test/test_subscription_callback.py
+++ b/tracetools_test/test/test_subscription_callback.py
@@ -5,8 +5,8 @@ from tracetools_test.utils import (
     cleanup_trace,
 )
 
+BASE_PATH = '/tmp'
 PKG = 'tracetools_test'
-
 subscription_callback_events = [
     'ros2:rclcpp_subscription_callback_start',
     'ros2:rclcpp_subscription_callback_end',
@@ -16,10 +16,9 @@ class TestSubscriptionCallback(unittest.TestCase):
 
     def test_callback(self):
         session_name_prefix = 'session-test-subscription-callback'
-        base_path = '/tmp'
         test_nodes = ['test_ping', 'test_pong']
 
-        exit_code, full_path = run_and_trace(base_path, session_name_prefix, subscription_callback_events, None, PKG, test_nodes)
+        exit_code, full_path = run_and_trace(BASE_PATH, session_name_prefix, subscription_callback_events, None, PKG, test_nodes)
         self.assertEqual(exit_code, 0)
 
         trace_events = get_trace_event_names(full_path)
diff --git a/tracetools_test/test/test_timer.py b/tracetools_test/test/test_timer.py
index 12e7c4c..950ce47 100644
--- a/tracetools_test/test/test_timer.py
+++ b/tracetools_test/test/test_timer.py
@@ -5,8 +5,8 @@ from tracetools_test.utils import (
     cleanup_trace,
 )
 
+BASE_PATH = '/tmp'
 PKG = 'tracetools_test'
-
 timer_events = [
     'ros2:rcl_timer_init',
     'ros2:rclcpp_timer_callback_added',
@@ -18,10 +18,9 @@ class TestTimer(unittest.TestCase):
 
     def test_all(self):
         session_name_prefix = 'session-test-timer-all'
-        base_path = '/tmp'
         test_nodes = ['test_timer']
 
-        exit_code, full_path = run_and_trace(base_path, session_name_prefix, timer_events, None, PKG, test_nodes)
+        exit_code, full_path = run_and_trace(BASE_PATH, session_name_prefix, timer_events, None, PKG, test_nodes)
         self.assertEqual(exit_code, 0)
 
         trace_events = get_trace_event_names(full_path)