diff --git a/launch/launch/actions/execute_process.py b/launch/launch/actions/execute_process.py
index ad4f089dc..334f61956 100644
--- a/launch/launch/actions/execute_process.py
+++ b/launch/launch/actions/execute_process.py
@@ -96,7 +96,7 @@ def __init__(
             'sigterm_timeout', default=5),
         sigkill_timeout: SomeSubstitutionsType = LaunchConfiguration(
             'sigkill_timeout', default=5),
-        emulate_tty: bool = False,
+        emulate_tty: bool = True,
         prefix: Optional[SomeSubstitutionsType] = None,
         output: Text = 'log',
         output_format: Text = '[{this.name}] {line}',
@@ -175,7 +175,7 @@ def __init__(
             as a string or a list of strings and Substitutions to be resolved
             at runtime, defaults to the LaunchConfiguration called
             'sigkill_timeout'
-        :param: emulate_tty emulate a tty (terminal), defaults to False, but can
+        :param: emulate_tty emulate a tty (terminal), defaults to True, but can
             be overridden with the LaunchConfiguration called 'emulate_tty',
             the value of which is evaluated as true or false according to
             :py:func:`evaluate_condition_expression`.
@@ -345,6 +345,8 @@ def __on_signal_process_event(
             raise RuntimeError('Signal event received before execution.')
         if self._subprocess_transport is None:
             raise RuntimeError('Signal event received before subprocess transport available.')
+        if self._subprocess_protocol is None:
+            raise RuntimeError('Signal event received before subprocess protocol available.')
         if self._subprocess_protocol.complete.done():
             # the process is done or is cleaning up, no need to signal
             self.__logger.debug(
@@ -390,6 +392,8 @@ def __on_process_stdin(
     def __on_process_stdout(
         self, event: ProcessIO
     ) -> Optional[SomeActionsType]:
+        if self.__stdout_buffer.closed:
+            raise RuntimeError('OnProcessIO (stdout) received after stdout buffer closed.')
         self.__stdout_buffer.write(event.text.decode(errors='replace'))
         self.__stdout_buffer.seek(0)
         last_line = None
@@ -409,6 +413,8 @@ def __on_process_stdout(
     def __on_process_stderr(
         self, event: ProcessIO
     ) -> Optional[SomeActionsType]:
+        if self.__stderr_buffer.closed:
+            raise RuntimeError('OnProcessIO (stderr) received after stderr buffer closed.')
         self.__stderr_buffer.write(event.text.decode(errors='replace'))
         self.__stderr_buffer.seek(0)
         last_line = None
diff --git a/launch/test/launch/actions/test_emulate_tty.py b/launch/test/launch/actions/test_emulate_tty.py
index b9d874d2b..81200a05d 100644
--- a/launch/test/launch/actions/test_emulate_tty.py
+++ b/launch/test/launch/actions/test_emulate_tty.py
@@ -36,7 +36,7 @@ def tty_expected_unless_windows():
 
 @pytest.mark.parametrize('test_input,expected', [
     # use the default defined by ExecuteProcess
-    (None, not tty_expected_unless_windows()),
+    (None, tty_expected_unless_windows()),
     # redundantly override the default via LaunchConfiguration
     ('true', tty_expected_unless_windows()),
     # override the default via LaunchConfiguration
diff --git a/launch_testing/launch_testing/test_runner.py b/launch_testing/launch_testing/test_runner.py
index 356f3a012..360f325db 100644
--- a/launch_testing/launch_testing/test_runner.py
+++ b/launch_testing/launch_testing/test_runner.py
@@ -59,7 +59,6 @@ def __init__(self,
         self._test_tr = threading.Thread(
             target=self._run_test,
             name='test_runner_thread',
-            daemon=True
         )
 
     def run(self):
@@ -160,6 +159,9 @@ def run(self):
 
         self._results.append(inactive_results)
 
+        # Join the test thread before returning to avoid it being daemonized.
+        self._test_tr.join()
+
         return self._results
 
     def _run_test(self):