diff --git a/binaries/data/mods/public/simulation/ai/petra/attackPlan.js b/binaries/data/mods/public/simulation/ai/petra/attackPlan.js
index 75f5c11e5d..690270d095 100644
--- a/binaries/data/mods/public/simulation/ai/petra/attackPlan.js
+++ b/binaries/data/mods/public/simulation/ai/petra/attackPlan.js
@@ -1329,7 +1329,7 @@ m.AttackPlan.prototype.update = function(gameState, events)
 				{	// if units are attacked, abandon their target (if it was a structure or a support) and retaliate
 					// also if our unit is attacking a range unit and the attacker is a melee unit, retaliate
 					var orderData = ourUnit.unitAIOrderData();
-					if (orderData.length !== 0 && orderData[0]["target"])
+					if (orderData && orderData.length && orderData[0]["target"])
 					{
 						var target = gameState.getEntityById(orderData[0]["target"]);
 						if (target && !target.hasClass("Structure") && !target.hasClass("Support"))
@@ -1462,14 +1462,14 @@ m.AttackPlan.prototype.update = function(gameState, events)
 			{
 				if (!maybeUpdate)
 				{
-					this.CheckCapture(ent);
+					this.CheckCapture(gameState, ent);
 					continue;
 				}
 				let deltat = (ent.unitAIState() === "INDIVIDUAL.COMBAT.APPROACHING") ? 10 : 5;
 				let lastAttackPlanUpdateTime = ent.getMetadata(PlayerID, "lastAttackPlanUpdateTime");
 				if (lastAttackPlanUpdateTime && (time - lastAttackPlanUpdateTime) < deltat)
 				{
-					this.CheckCapture(ent);
+					this.CheckCapture(gameState, ent);
 					continue;
 				}
 			}
@@ -1636,7 +1636,7 @@ m.AttackPlan.prototype.update = function(gameState, events)
 						this.unitCollection.forEach( function (unit) {
 							if (!unit.position())
 								return;
-							if (unit.unitAIState().split(".")[1] !== "COMBAT" || unit.unitAIOrderData().length == 0
+							if (unit.unitAIState().split(".")[1] !== "COMBAT" || !unit.unitAIOrderData().length
 								|| !unit.unitAIOrderData()[0]["target"])
 								return;
 							var dist = API3.SquareVectorDistance(unit.position(), ent.position());
@@ -1787,22 +1787,22 @@ m.AttackPlan.prototype.debugAttack = function()
 	API3.warn("------------------------------");
 };
 
-m.AttackPlan.prototype.CheckCapture = function(ent)
+m.AttackPlan.prototype.CheckCapture = function(gameState, ent)
 {
 	let state = ent.unitAIState();
 	if (!state || !state.split(".")[1] || state.split(".")[1] !== "COMBAT")
 		return;
 	let orderData = ent.unitAIOrderData();
-	if (!orderData || !orderData.target || !orderData.attackType || orderData.attackType !== "Capture")
+	if (!orderData || !orderData.length || !orderData[0].target || !orderData[0].attackType || orderData[0].attackType !== "Capture")
 		return;
-	let target = gameState.getEntityById(orderData.target);
+	let target = gameState.getEntityById(orderData[0].target);
 	if (!target)
 		return;
 
 	// For the time being, do not try to capture rams
 	if (target.hasClass("Siege") && target.hasClass("Melee"))
 	{
-		ent.attack(target.id(), false);
+		ent.attack(orderData[0].target, false);
 		return;
 	}
 
@@ -1814,7 +1814,7 @@ m.AttackPlan.prototype.CheckCapture = function(ent)
 	// but TODO need to know how many units are currently capturing this target
 	// For the time being, we check on our army length
 	if (target.garrisoned() && target.garrisoned().length > Math.floor(this.unitCollection.length / 2))
-		ent.attack(target.id(), false);
+		ent.attack(orderData[0].target, false);
 };
 
 m.AttackPlan.prototype.Serialize = function()
diff --git a/binaries/data/mods/public/simulation/ai/petra/defenseArmy.js b/binaries/data/mods/public/simulation/ai/petra/defenseArmy.js
index 5994eab69f..ad81236449 100644
--- a/binaries/data/mods/public/simulation/ai/petra/defenseArmy.js
+++ b/binaries/data/mods/public/simulation/ai/petra/defenseArmy.js
@@ -25,9 +25,9 @@ m.DefenseArmy.prototype.assignUnit = function (gameState, entID)
 	var distMin = undefined;
 	var idMinAll = undefined;
 	var distMinAll = undefined; 
-	for (var id of this.foeEntities)
+	for (let id of this.foeEntities)
 	{
-		var eEnt = gameState.getEntityById(id);
+		let eEnt = gameState.getEntityById(id);
 		if (!eEnt || !eEnt.position())	// probably can't happen.
 			continue;
 
@@ -43,7 +43,7 @@ m.DefenseArmy.prototype.assignUnit = function (gameState, entID)
 			|| (this.assignedAgainst[id].length > 5 && !eEnt.hasClass("Hero") && !eEnt.hasClass("Siege")))
 			continue;
 
-		var dist = API3.SquareVectorDistance(ent.position(), eEnt.position());
+		let dist = API3.SquareVectorDistance(ent.position(), eEnt.position());
 		if (idMinAll === undefined || dist < distMinAll)
 		{
 			idMinAll = id;
@@ -65,14 +65,15 @@ m.DefenseArmy.prototype.assignUnit = function (gameState, entID)
 	else
 		return false;
 
-	var ownIndex = gameState.ai.accessibility.getAccessValue(ent.position());
-	var foePosition = gameState.getEntityById(idFoe).position();
-	var foeIndex = gameState.ai.accessibility.getAccessValue(foePosition);
+	let ownIndex = gameState.ai.accessibility.getAccessValue(ent.position());
+	let foeEnt = gameState.getEntityById(idFoe);
+	let foePosition = foeEnt.position();
+	let foeIndex = gameState.ai.accessibility.getAccessValue(foePosition);
 	if (ownIndex == foeIndex || ent.hasClass("Ship"))
 	{
 		this.assignedTo[entID] = idFoe;
 		this.assignedAgainst[idFoe].push(entID);
-		ent.attack(idFoe);
+		ent.attack(idFoe, (!foeEnt.hasClass("Siege") || !foeEnt.hasClass("Melee")));
 	}
 	else
 		gameState.ai.HQ.navalManager.requireTransport(gameState, ent, ownIndex, foeIndex, foePosition);
@@ -105,9 +106,15 @@ m.DefenseArmy.prototype.update = function (gameState)
 		let ent = gameState.getEntityById(entId);
 		if (!ent)
 			continue;
-		let orders = ent.unitAIOrderData();
-		if (orders.length == 0 && !ent.getMetadata(PlayerID, "transport"))
+		let orderData = ent.unitAIOrderData();
+		if (!orderData.length && !ent.getMetadata(PlayerID, "transport"))
 			this.assignUnit(gameState, entId);
+		else if (orderData.length && orderData[0].target && orderData[0].attackType && orderData[0].attackType === "Capture")
+		{
+			let target = gameState.getEntityById(orderData[0].target);
+			if (target && target.hasClass("Siege") && target.hasClass("Melee"))
+				ent.attack(orderData[0].target, false);
+		}
 	}
 
 	return this.onUpdate(gameState);