diff --git a/Defs/Ammo/Advanced/164x284mmDemoShell.xml b/Defs/Ammo/Advanced/164x284mmDemoShell.xml
index 85e443b68c..65b04b9760 100644
--- a/Defs/Ammo/Advanced/164x284mmDemoShell.xml
+++ b/Defs/Ammo/Advanced/164x284mmDemoShell.xml
@@ -80,7 +80,7 @@
 			<armorPenetrationBlunt>0</armorPenetrationBlunt>
 			<speed>61</speed>
 			<flyOverhead>false</flyOverhead>
-			<explosionRadius>2</explosionRadius>
+			<explosionRadius>3.9</explosionRadius>
 			<soundExplode>ThumpCannon_Impact</soundExplode>
 			<soundHitThickRoof>Artillery_HitThickRoof</soundHitThickRoof>
 			<soundImpactAnticipate>MortarRound_PreImpact</soundImpactAnticipate>
@@ -116,7 +116,7 @@
 			<speed>1</speed>
 			<gravityFactor>50</gravityFactor>
 			<flyOverhead>false</flyOverhead>
-			<explosionRadius>2</explosionRadius>
+			<explosionRadius>2.9</explosionRadius>
 			<soundExplode>ThumpCannon_Impact</soundExplode>
 			<soundHitThickRoof>Artillery_HitThickRoof</soundHitThickRoof>
 			<soundImpactAnticipate>MortarRound_PreImpact</soundImpactAnticipate>