diff --git a/doc/release_notes.rst b/doc/release_notes.rst
index 2a009fe5..325462ad 100644
--- a/doc/release_notes.rst
+++ b/doc/release_notes.rst
@@ -11,6 +11,8 @@ Release Notes
 .. Upcoming Release
 .. ================
 
+* 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/prepare_sector_network.py b/scripts/prepare_sector_network.py
index a83e2d12..fcf41d88 100644
--- a/scripts/prepare_sector_network.py
+++ b/scripts/prepare_sector_network.py
@@ -604,16 +604,14 @@ def add_carrier_buses(n, carrier, nodes=None):
 
             suffix = " primary"
 
-        else:
-
-            n.madd(
-                "Generator",
-                nodes + suffix,
-                bus=nodes + suffix,
-                p_nom_extendable=True,
-                carrier=carrier + suffix,
-                marginal_cost=costs.at[carrier, "fuel"],
-            )
+        n.madd(
+            "Generator",
+            nodes + suffix,
+            bus=nodes + suffix,
+            p_nom_extendable=True,
+            carrier=carrier + suffix,
+            marginal_cost=costs.at[carrier, "fuel"],
+        )
 
 
 # TODO: PyPSA-Eur merge issue