diff --git a/gnpy/core/parameters.py b/gnpy/core/parameters.py
index 851ee6e3e..76735c8e9 100644
--- a/gnpy/core/parameters.py
+++ b/gnpy/core/parameters.py
@@ -74,7 +74,8 @@ def to_json(self):
         return {"method": self.method,
                 "dispersion_tolerance": self.dispersion_tolerance,
                 "phase_shift_tolerance": self.phase_shift_tolerance,
-                "computed_channels": self.computed_channels}
+                "computed_channels": self.computed_channels,
+                "computed_number_of_channels": self.computed_number_of_channels}
 
 
 class SimParams(Parameters):