diff --git a/OpenRA.Game/GameRules/WeaponInfo.cs b/OpenRA.Game/GameRules/WeaponInfo.cs
index e512c8c153..133d35dc47 100644
--- a/OpenRA.Game/GameRules/WeaponInfo.cs
+++ b/OpenRA.Game/GameRules/WeaponInfo.cs
@@ -24,6 +24,7 @@ namespace OpenRA.GameRules
 		public int[] RangeModifiers;
 		public int Facing;
 		public WPos Source;
+		public Func<WPos> CurrentSource;
 		public Actor SourceActor;
 		public WPos PassiveTarget;
 		public Target GuidedTarget;
diff --git a/OpenRA.Mods.Common/Traits/Armament.cs b/OpenRA.Mods.Common/Traits/Armament.cs
index 4b86abe678..3c64116f34 100644
--- a/OpenRA.Mods.Common/Traits/Armament.cs
+++ b/OpenRA.Mods.Common/Traits/Armament.cs
@@ -187,7 +187,7 @@ namespace OpenRA.Mods.Common.Traits
 				return null;
 
 			var barrel = Barrels[Burst % Barrels.Length];
-			var muzzlePosition = self.CenterPosition + MuzzleOffset(self, barrel);
+			Func<WPos> muzzlePosition = () => self.CenterPosition + MuzzleOffset(self, barrel);
 			var legacyFacing = MuzzleOrientation(self, barrel).Yaw.Angle / 4;
 
 			var args = new ProjectileArgs
@@ -204,7 +204,8 @@ namespace OpenRA.Mods.Common.Traits
 				RangeModifiers = self.TraitsImplementing<IRangeModifier>()
 					.Select(a => a.GetRangeModifier()).ToArray(),
 
-				Source = muzzlePosition,
+				Source = muzzlePosition(),
+				CurrentSource = muzzlePosition,
 				SourceActor = self,
 				PassiveTarget = target.CenterPosition,
 				GuidedTarget = target
diff --git a/OpenRA.Mods.Common/Traits/ThrowsShrapnel.cs b/OpenRA.Mods.Common/Traits/ThrowsShrapnel.cs
index f0ea965dd9..b18935a65e 100644
--- a/OpenRA.Mods.Common/Traits/ThrowsShrapnel.cs
+++ b/OpenRA.Mods.Common/Traits/ThrowsShrapnel.cs
@@ -70,6 +70,7 @@ namespace OpenRA.Mods.Common.Traits
 							.Select(a => a.GetRangeModifier()).ToArray(),
 
 						Source = self.CenterPosition,
+						CurrentSource = () => self.CenterPosition,
 						SourceActor = self,
 						PassiveTarget = self.CenterPosition + new WVec(range, 0, 0).Rotate(rotation)
 					};
diff --git a/OpenRA.Mods.D2k/Traits/SpiceBloom.cs b/OpenRA.Mods.D2k/Traits/SpiceBloom.cs
index baeb4ae926..07280e08ca 100644
--- a/OpenRA.Mods.D2k/Traits/SpiceBloom.cs
+++ b/OpenRA.Mods.D2k/Traits/SpiceBloom.cs
@@ -136,6 +136,7 @@ namespace OpenRA.Mods.D2k.Traits
 						.Select(a => a.GetInaccuracyModifier()).ToArray(),
 
 					Source = self.CenterPosition,
+					CurrentSource = () => self.CenterPosition,
 					SourceActor = self,
 					PassiveTarget = self.World.Map.CenterOfCell(cell.Value)
 				};