diff --git a/src/psij/launchers/script_based_launcher.py b/src/psij/launchers/script_based_launcher.py
index 9d11f932..505b3c0e 100644
--- a/src/psij/launchers/script_based_launcher.py
+++ b/src/psij/launchers/script_based_launcher.py
@@ -204,4 +204,7 @@ def is_launcher_failure(self, output: str) -> bool:
 
     def get_launcher_failure_message(self, output: str) -> str:
         """See :func:`~psij.Launcher.get_launcher_failure_message`."""
-        return '\n'.join(output.split('\n')[:-2])
+        # If, according to the above, it is a launcher failure, then
+        # the magic line should not be present (aka, all of the output
+        # is the failure).
+        return output
diff --git a/src/psij/launchers/scripts/mpi_launch.sh b/src/psij/launchers/scripts/mpi_launch.sh
index 153fc2b6..31c45233 100644
--- a/src/psij/launchers/scripts/mpi_launch.sh
+++ b/src/psij/launchers/scripts/mpi_launch.sh
@@ -15,12 +15,29 @@ fi
 
 pre_launch
 
+filter_out() {
+    sed -nE 's/^\[[^]]+\]<stdout>:(.*)/\1/p'
+}
+
+filter_err() {
+    sed -nE 's/^\[[^]]+\]<stderr>:(.*)/\1/p'
+}
+
+filter_out_5() {
+    sed -nE 's/^\[[^]]+\]<stdout>: (.*)/\1/p'
+}
+
+filter_err_5() {
+    sed -nE 's/^\[[^]]+\]<stderr>: (.*)/\1/p'
+}
+
 set +e
 if [ "$IS_OPENMPI_5" == "1" ]; then
-    # there is no -q parameter in OMPI 5
-    mpirun --oversubscribe -n $_PSI_J_PROCESS_COUNT "$@" 1>$_PSI_J_STDOUT 2>$_PSI_J_STDERR <$_PSI_J_STDIN
+    mpirun --oversubscribe --output TAG -n $_PSI_J_PROCESS_COUNT "$@" \
+        1> >(filter_out_5 > $_PSI_J_STDOUT) 2> >(filter_err_5 > $_PSI_J_STDERR) <$_PSI_J_STDIN
 elif [ "$IS_OPENMPI" == "1" ]; then
-    mpirun --oversubscribe -q -n $_PSI_J_PROCESS_COUNT "$@" 1>$_PSI_J_STDOUT 2>$_PSI_J_STDERR <$_PSI_J_STDIN
+    mpirun --oversubscribe --tag-output -q -n $_PSI_J_PROCESS_COUNT "$@" \
+        1> >(filter_out > "$_PSI_J_STDOUT") 2> >(filter_err > $_PSI_J_STDERR) <$_PSI_J_STDIN
 else
     mpirun -n $_PSI_J_PROCESS_COUNT "$@" 1>$_PSI_J_STDOUT 2>$_PSI_J_STDERR <$_PSI_J_STDIN
 fi
diff --git a/tests/_test_tools.py b/tests/_test_tools.py
index a5666af9..f780081f 100644
--- a/tests/_test_tools.py
+++ b/tests/_test_tools.py
@@ -28,8 +28,13 @@ def _read_file(path: Optional[Path]) -> str:
     if path is None:
         return ''
 
-    with open(path, 'r') as f:
-        return f.read()
+    try:
+        with open(path, 'r') as f:
+            return f.read()
+    except FileNotFoundError:
+        return '<missing>'
+    except Exception as ex:
+        return f'<error: {ex}>'
 
 
 def assert_completed(job: Job, status: Optional[JobStatus], attached: bool = False) -> None:
diff --git a/tests/test_executor.py b/tests/test_executor.py
index 50f9ebf3..ac6bef0e 100644
--- a/tests/test_executor.py
+++ b/tests/test_executor.py
@@ -36,6 +36,22 @@ def test_simple_job_redirect(execparams: ExecutorTestParams) -> None:
         assert contents == '_x_'
 
 
+def test_stderr_redirect(execparams: ExecutorTestParams) -> None:
+    _make_test_dir()
+    with TemporaryDirectory(dir=Path.home() / '.psij' / 'test') as td:
+        outp = Path(td, 'stderr.txt')
+        job = Job(JobSpec(executable='/bin/bash', arguments=['-c', 'echo -n _x_ 1>&2'],
+                          stderr_path=outp))
+        ex = _get_executor_instance(execparams, job)
+        ex.submit(job)
+        status = job.wait(timeout=_get_timeout(execparams))
+        assert_completed(job, status)
+        f = outp.open("r")
+        contents = f.read()
+        f.close()
+        assert contents == '_x_'
+
+
 def test_attach(execparams: ExecutorTestParams) -> None:
     job1 = Job(JobSpec(executable='/bin/sleep', arguments=['1']))
     ex = _get_executor_instance(execparams, job1)