diff --git a/composition/test/test_dlopen_composition.py.in b/composition/test/test_dlopen_composition.py.in
index 19b9e5dce..9fca267d3 100644
--- a/composition/test/test_dlopen_composition.py.in
+++ b/composition/test/test_dlopen_composition.py.in
@@ -21,10 +21,13 @@ import launch_testing
 import launch_testing.actions
 import launch_testing.asserts
 import launch_testing_ros
+from launch_testing_ros.actions import EnableRmwIsolation
 
 
 def generate_test_description():
-    launch_description = LaunchDescription()
+    launch_description = LaunchDescription([
+        EnableRmwIsolation(),
+    ])
     process_under_test = ExecuteProcess(
         cmd=[
             '@DLOPEN_COMPOSITION_EXECUTABLE@',
diff --git a/composition/test/test_linktime_composition.py.in b/composition/test/test_linktime_composition.py.in
index ceae41402..50f979f99 100644
--- a/composition/test/test_linktime_composition.py.in
+++ b/composition/test/test_linktime_composition.py.in
@@ -24,10 +24,13 @@ import launch_testing
 import launch_testing.actions
 import launch_testing.asserts
 import launch_testing_ros
+from launch_testing_ros.actions import EnableRmwIsolation
 
 
 def generate_test_description():
-    launch_description = LaunchDescription()
+    launch_description = LaunchDescription([
+        EnableRmwIsolation(),
+    ])
     process_under_test = ExecuteProcess(
         cmd=['@LINKTIME_COMPOSITION_EXECUTABLE@'],
         name='test_linktime_composition',