diff --git a/ns3 b/ns3
index eb4302a26..e90991eeb 100755
--- a/ns3
+++ b/ns3
@@ -789,8 +789,6 @@ def run_step(args, target_to_run, target_args):
             commands = (args.command_template % target_to_run).split()
             target_to_run = commands[0]
             target_args = commands[1:] + target_args
-            if target_to_run in ["mpiexec", "mpirun"]:
-                target_args = ["--allow-run-as-root"] + target_args
 
     program_arguments = [*debugging_software, target_to_run, *target_args]
 
diff --git a/utils/tests/gitlab-ci.yml b/utils/tests/gitlab-ci.yml
index 7d85bf9f0..d6b9bbc66 100644
--- a/utils/tests/gitlab-ci.yml
+++ b/utils/tests/gitlab-ci.yml
@@ -37,6 +37,9 @@ stages:
     - mkdir -p $CCACHE_BASEDIR_VALUE
     - export CCACHE_BASEDIR=${PWD}
     - export CCACHE_DIR=${PWD}/$CCACHE_BASEDIR_VALUE
+    - export OMPI_ALLOW_RUN_AS_ROOT=1
+    - export OMPI_ALLOW_RUN_AS_ROOT_CONFIRM=1
+    - export OMPI_MCA_rmaps_base_oversubscribe=1
     - CXX=$COMPILER ./ns3 configure -d $MODE -GNinja --enable-examples --enable-tests --enable-asserts
     - ./ns3 build
     - if [ "$MODE" != "debug" ]; then ./test.py -n; fi