diff --git a/Biotech/Patches/DamageDefs/Damages_Misc.xml b/Biotech/Patches/DamageDefs/Damages_Misc.xml
index dfaa9a3b85..b4738bff50 100644
--- a/Biotech/Patches/DamageDefs/Damages_Misc.xml
+++ b/Biotech/Patches/DamageDefs/Damages_Misc.xml
@@ -36,4 +36,15 @@
 		</value>
 	</Operation>
 
+	<!-- ========== ToxGas ========== -->
+
+	<Operation Class="PatchOperationAddModExtension">
+		<xpath>Defs/DamageDef[defName="ToxGas"]</xpath>
+		<value>
+			<li Class="CombatExtended.DamageDefExtensionCE">
+				<isHarmful>true</isHarmful>
+			</li>
+		</value>
+	</Operation>
+
 </Patch>
\ No newline at end of file
diff --git a/ModPatches/BiologicalWarfare/Patches/Patches.xml b/ModPatches/BiologicalWarfare/Patches/Patches.xml
index eb1f4d4ec8..ea47d03794 100644
--- a/ModPatches/BiologicalWarfare/Patches/Patches.xml
+++ b/ModPatches/BiologicalWarfare/Patches/Patches.xml
@@ -289,4 +289,68 @@
 			defName="USH_SleepingSicknessGrenadeLauncher" or
 			defName="USH_SleepingSicknessGrenadeBullet"]</xpath>
 	</Operation>
+
+	<!-- ========== Patch DamageDefs to allow sieges to use mortars ========== -->
+    <Operation Class="PatchOperationAddModExtension">
+		<xpath>Defs/DamageDef[defName="USH_FleshBreakerDamage"]</xpath>
+		<value>
+			<li Class="CombatExtended.DamageDefExtensionCE">
+				<isHarmful>true</isHarmful>
+			</li>
+		</value>
+	</Operation>
+
+    <Operation Class="PatchOperationAddModExtension">
+		<xpath>Defs/DamageDef[defName="USH_FluDamage"]</xpath>
+		<value>
+			<li Class="CombatExtended.DamageDefExtensionCE">
+				<isHarmful>true</isHarmful>
+			</li>
+		</value>
+	</Operation>
+
+    <Operation Class="PatchOperationAddModExtension">
+		<xpath>Defs/DamageDef[defName="USH_MalariaDamage"]</xpath>
+		<value>
+			<li Class="CombatExtended.DamageDefExtensionCE">
+				<isHarmful>true</isHarmful>
+			</li>
+		</value>
+	</Operation>
+
+    <Operation Class="PatchOperationAddModExtension">
+		<xpath>Defs/DamageDef[defName="USH_NecroaDamage"]</xpath>
+		<value>
+			<li Class="CombatExtended.DamageDefExtensionCE">
+				<isHarmful>true</isHarmful>
+			</li>
+		</value>
+	</Operation>
+
+    <Operation Class="PatchOperationAddModExtension">
+		<xpath>Defs/DamageDef[defName="USH_PlagueDamage"]</xpath>
+		<value>
+			<li Class="CombatExtended.DamageDefExtensionCE">
+				<isHarmful>true</isHarmful>
+			</li>
+		</value>
+	</Operation>
+
+    <Operation Class="PatchOperationAddModExtension">
+		<xpath>Defs/DamageDef[defName="USH_ScariaDamage"]</xpath>
+		<value>
+			<li Class="CombatExtended.DamageDefExtensionCE">
+				<isHarmful>true</isHarmful>
+			</li>
+		</value>
+	</Operation>
+    
+    <Operation Class="PatchOperationAddModExtension">
+		<xpath>Defs/DamageDef[defName="USH_SleepingSicknessDamage"]</xpath>
+		<value>
+			<li Class="CombatExtended.DamageDefExtensionCE">
+				<isHarmful>true</isHarmful>
+			</li>
+		</value>
+	</Operation>
 </Patch>
\ No newline at end of file