diff --git a/bfps/NavierStokes.py b/bfps/NavierStokes.py
index 901cbb058050b6f6dc0831aca1c78c3553ec00b0..b23a70a94b54920c340ae572eac662fb2679b7ee 100644
--- a/bfps/NavierStokes.py
+++ b/bfps/NavierStokes.py
@@ -458,7 +458,6 @@ class NavierStokes(bfps.fluid_base.fluid_particle_base):
             neighbours = self.parameters[interpolator[s] + '_neighbours']
             if type(kcut) == list:
                 self.parameters['tracers{0}_kcut'.format(s0 + s)] = kcut[s]
-            self.parameters['tracers{0}_acc_on'.format(s0 + s)] = not type(acc_name) == type(None)
             self.parameters['tracers{0}_interpolator'.format(s0 + s)] = interpolator[s]
             self.parameters['tracers{0}_integration_steps'.format(s0 + s)] = integration_steps[s]
             self.file_datasets_grow += """