diff --git a/machines/derecho/config_machines.xml b/machines/derecho/config_machines.xml
index 633fe74d..6f9d6fd6 100644
--- a/machines/derecho/config_machines.xml
+++ b/machines/derecho/config_machines.xml
@@ -21,11 +21,11 @@
     <MPI_GPU_WRAPPER_SCRIPT>get_local_rank</MPI_GPU_WRAPPER_SCRIPT>
     <PROJECT_REQUIRED>TRUE</PROJECT_REQUIRED>
     <mpirun mpilib="default">
-      <executable>mpiexec</executable>
+      <executable>mpibind</executable>
       <arguments>
         <arg name="label"> --label</arg>
-        <arg name="buffer"> --line-buffer</arg>
-        <arg name="num_tasks" > -n {{ total_tasks }}</arg>
+	<arg name="buffer"> --line-buffer</arg>
+	<arg name="separator"> -- </arg>
       </arguments>
     </mpirun>
     <module_system type="module" allow_error="true">