Index: binaries/data/mods/public/simulation/ai/petra/baseManager.js
===================================================================
--- binaries/data/mods/public/simulation/ai/petra/baseManager.js
+++ binaries/data/mods/public/simulation/ai/petra/baseManager.js
@@ -180,8 +180,7 @@
 		let medium = this.dropsiteSupplies[type].medium;
 		let faraway = this.dropsiteSupplies[type].faraway;
 
-		resources.forEach(function(supply)
-		{
+		resources.forEach(supply => {
 			if (!supply.position())
 				return;
 			// Moving resources and fields are treated differently.
@@ -194,6 +193,10 @@
 			let dist = API3.SquareVectorDistance(supply.position(), dropsitePos);
 			if (dist < maxDistResourceSquare)
 			{
+				supply.setMetadata(PlayerID, "assignedResource", type);
+				supply.setMetadata(PlayerID, "base", this.ID);
+				if (supply.id() === 2886)
+						warn("Adding " + supply.id() + " for " + PlayerID);
 				if (dist < maxDistResourceSquare/16)        // distmax/4
 					nearby.push({ "dropsite": dropsiteId, "id": supply.id(), "ent": supply, "dist": dist });
 				else if (dist < maxDistResourceSquare/4)    // distmax/2
@@ -233,6 +236,18 @@
 	});
 };
 
+PETRA.BaseManager.prototype.removeFromAssignedDropsite = function(ent)
+{
+	for (const type in this.dropsiteSupplies)
+		for (const proxim in this.dropsiteSupplies[type])
+		{
+			const resourcesList = this.dropsiteSupplies[type][proxim];
+			for (let i = 0; i < resourcesList.length; ++i)
+				if (resourcesList[i].id === ent.id())
+					resourcesList.splice(i--, 1);
+		}
+}
+
 // completely remove the dropsite resources from our list.
 PETRA.BaseManager.prototype.removeDropsite = function(gameState, ent)
 {
Index: binaries/data/mods/public/simulation/ai/petra/basesManager.js
===================================================================
--- binaries/data/mods/public/simulation/ai/petra/basesManager.js
+++ binaries/data/mods/public/simulation/ai/petra/basesManager.js
@@ -132,6 +132,8 @@
 			evt.metadata[PlayerID].base)
 		{
 			const ent = evt.entityObj;
+			if (evt?.metadata?.[PlayerID]?.assignedResource)
+				this.getBaseByID(evt.metadata[PlayerID].base).removeFromAssignedDropsite(ent);
 			if (ent.owner() != PlayerID)
 				continue;
 			// A new base foundation was created and destroyed on the same (AI) turn