diff --git a/bfps/DNS.py b/bfps/DNS.py
index 3d531005f93bdd684a8f2e678e0b4be74e9b6af9..d1ffb1eb22b1da28043f77109af648c9a633b4ab 100644
--- a/bfps/DNS.py
+++ b/bfps/DNS.py
@@ -379,7 +379,8 @@ class DNS(_code):
     def write_par(
             self,
             iter0 = 0,
-            particle_ic = None):
+            particle_ic = None,
+            particles_off = False):
         assert (self.parameters['niter_todo'] % self.parameters['niter_stat'] == 0)
         assert (self.parameters['niter_todo'] % self.parameters['niter_out']  == 0)
         assert (self.parameters['niter_out']  % self.parameters['niter_stat'] == 0)
@@ -426,7 +427,7 @@ class DNS(_code):
                                                  4),
                                      dtype = np.int64)
             ofile['checkpoint'] = int(0)
-        if self.dns_type in ['NSVE', 'NSVE_no_output']:
+        if (self.dns_type in ['NSVE', 'NSVE_no_output']) or particles_off:
             return None
 
         if type(particle_ic) == type(None):