diff --git a/doc/release_notes.rst b/doc/release_notes.rst
index 634209c7..e1244c96 100644
--- a/doc/release_notes.rst
+++ b/doc/release_notes.rst
@@ -46,6 +46,8 @@ Upcoming Release
 
 * Add VOM as marginal cost to PtX processes.
 
+* Add pelletizing costs for biomass boilers.
+
 * The ``mock_snakemake`` function can now be used with a Snakefile from a different directory using the new ``root_dir`` argument.
 
 * Switch to using hydrogen and electricity inputs for Haber-Bosch from https://github.com/PyPSA/technology-data.
diff --git a/scripts/prepare_sector_network.py b/scripts/prepare_sector_network.py
index e9d97ade..edd7e2af 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -2331,6 +2331,7 @@ def add_biomass(n, costs):
                 efficiency=costs.at["biomass boiler", "efficiency"],
                 capital_cost=costs.at["biomass boiler", "efficiency"]
                 * costs.at["biomass boiler", "fixed"],
+                marginal_cost=costs.at["biomass boiler", "pelletizing cost"],
                 lifetime=costs.at["biomass boiler", "lifetime"],
             )