diff --git a/namelists/icon_atmosphere_real-from-ideal_01.namelist b/namelists/icon_atmosphere_real-from-ideal_01.namelist
index 41eb39e5c1c8de430527025e7d626edc9a46dfe4..094401dcf0df5a9d5e7132b43b1863ef99b6fd85 100644
--- a/namelists/icon_atmosphere_real-from-ideal_01.namelist
+++ b/namelists/icon_atmosphere_real-from-ideal_01.namelist
@@ -1,7 +1,7 @@
 &run_nml
-    ltestcase                   = .false.
-    dtime                       =  300
-    output                      = 'nml'
+    ltestcase                   = .TRUE.        ! idealized testcase runs
+    dtime                       = 300           ! time step of 300 seconds
+    output                      = 'nml'         ! use output nameslists
     msg_level                   = 15
     num_lev                     = 31
     lvert_nest                  = .false.
@@ -42,6 +42,10 @@
     dt_checkpoint = '%checkpoint_time%'
 /
 
+&parallel_nml
+    nproma                      = 16
+/
+
 ! the following two output files are used to initialize the next run
 &output_nml
     file_interval               = 'PT3600S'