diff --git a/doc/release_notes.rst b/doc/release_notes.rst
index 325462ad..f8460e14 100644
--- a/doc/release_notes.rst
+++ b/doc/release_notes.rst
@@ -11,6 +11,8 @@ Release Notes
 .. Upcoming Release
 .. ================
 
+* bugfix: The carrier of stores was silently overwritten by their bus_carrier as a side effect when building the co2 constraints
+
 * bugfix: The oil generator was incorrectly dropped when the config `oil_refining_emissions` was greater than zero. This was the default behaviour in 0.12.0.
 
 PyPSA-Eur 0.12.0 (30th August 2024)
diff --git a/scripts/solve_network.py b/scripts/solve_network.py
index c70d4d3c..bdc10dd1 100644
--- a/scripts/solve_network.py
+++ b/scripts/solve_network.py
@@ -330,8 +330,8 @@ def add_carbon_constraint(n, snapshots):
             continue
 
         # stores
-        n.stores["carrier"] = n.stores.bus.map(n.buses.carrier)
-        stores = n.stores.query("carrier in @emissions.index and not e_cyclic")
+        bus_carrier = n.stores.bus.map(n.buses.carrier)
+        stores = n.stores[bus_carrier.isin(emissions.index) & ~n.stores.e_cyclic]
         if not stores.empty:
             last = n.snapshot_weightings.reset_index().groupby("period").last()
             last_i = last.set_index([last.index, last.timestep]).index
@@ -356,8 +356,8 @@ def add_carbon_budget_constraint(n, snapshots):
             continue
 
         # stores
-        n.stores["carrier"] = n.stores.bus.map(n.buses.carrier)
-        stores = n.stores.query("carrier in @emissions.index and not e_cyclic")
+        bus_carrier = n.stores.bus.map(n.buses.carrier)
+        stores = n.stores[bus_carrier.isin(emissions.index) & ~n.stores.e_cyclic]
         if not stores.empty:
             last = n.snapshot_weightings.reset_index().groupby("period").last()
             last_i = last.set_index([last.index, last.timestep]).index
@@ -1000,8 +1000,8 @@ def add_co2_atmosphere_constraint(n, snapshots):
             continue
 
         # stores
-        n.stores["carrier"] = n.stores.bus.map(n.buses.carrier)
-        stores = n.stores.query("carrier in @emissions.index and not e_cyclic")
+        bus_carrier = n.stores.bus.map(n.buses.carrier)
+        stores = n.stores[bus_carrier.isin(emissions.index) & ~n.stores.e_cyclic]
         if not stores.empty:
             last_i = snapshots[-1]
             lhs = n.model["Store-e"].loc[last_i, stores.index]