diff --git a/tardis/transport/montecarlo/base.py b/tardis/transport/montecarlo/base.py
index 46f3430ed56..c02a50fb4a8 100644
--- a/tardis/transport/montecarlo/base.py
+++ b/tardis/transport/montecarlo/base.py
@@ -186,6 +186,7 @@ def run(
             self.montecarlo_configuration,
             transport_state.radfield_mc_estimators,
             self.spectrum_frequency_grid.value,
+            transport_state.rpacket_tracker,
             number_of_vpackets,
             iteration=iteration,
             show_progress_bars=show_progress_bars,
diff --git a/tardis/transport/montecarlo/montecarlo_main_loop.py b/tardis/transport/montecarlo/montecarlo_main_loop.py
index 82043a060f8..c82b55d5165 100644
--- a/tardis/transport/montecarlo/montecarlo_main_loop.py
+++ b/tardis/transport/montecarlo/montecarlo_main_loop.py
@@ -33,6 +33,7 @@ def montecarlo_main_loop(
     montecarlo_configuration,
     estimators,
     spectrum_frequency_grid,
+    rpacket_trackers,
     number_of_vpackets,
     iteration,
     show_progress_bars,