diff --git a/binaries/data/mods/public/simulation/components/UnitAI.js b/binaries/data/mods/public/simulation/components/UnitAI.js
index f25e4691e0..54ea5fbd40 100644
--- a/binaries/data/mods/public/simulation/components/UnitAI.js
+++ b/binaries/data/mods/public/simulation/components/UnitAI.js
@@ -1512,7 +1512,7 @@ var UnitFsmSpec = {
 			"APPROACHING": {
 				"enter": function() {
 					this.SelectAnimation("move");
-					
+
 					this.gatheringTarget = this.order.data.target;	// temporary, deleted in "leave".
 
 					// check that we can gather from the resource we're supposed to gather from.
@@ -1657,20 +1657,21 @@ var UnitFsmSpec = {
 			"GATHERING": {
 				"enter": function() {
 					this.gatheringTarget = this.order.data.target;	// deleted in "leave".
-					
+
 					// Check if the resource is full.
-					if (this.gatheringTarget) {
+					if (this.gatheringTarget)
+					{
 						// Check that we can gather from the resource we're supposed to gather from.
 						// Will only be added if we're not already in.
 						var cmpSupply = Engine.QueryInterface(this.gatheringTarget, IID_ResourceSupply);
 						if (!cmpSupply || !cmpSupply.AddGatherer(this.entity))
 						{
-							this.gatheringTarget = -1;
+							this.gatheringTarget = INVALID_ENTITY;
 							this.StartTimer(0);
 							return false;
 						}
 					}
-					
+
 					// If this order was forced, the player probably gave it, but now we've reached the target
 					//	switch to an unforced order (can be interrupted by attacks)
 					this.order.data.force = false;
@@ -1690,7 +1691,7 @@ var UnitFsmSpec = {
 							this.StartTimer(0);
 							return false;
 						}
-						
+
 						// No rate, give up on gathering
 						this.FinishOrder();
 						return true;
@@ -1717,13 +1718,12 @@ var UnitFsmSpec = {
 
 				"leave": function() {
 					this.StopTimer();
-					
+
 					var cmpSupply = Engine.QueryInterface(this.gatheringTarget, IID_ResourceSupply);
 					if (cmpSupply)
 						cmpSupply.RemoveGatherer(this.entity);
-					this.gatheringTarget = -1;
 					delete this.gatheringTarget;
-					
+
 					// Show the carried resource, if we've gathered anything.
 					this.SetGathererAnimationOverride();
 				},
@@ -1731,72 +1731,75 @@ var UnitFsmSpec = {
 				"Timer": function(msg) {
 					var resourceTemplate = this.order.data.template;
 					var resourceType = this.order.data.type;
-					
+
 					var cmpSupply = Engine.QueryInterface(this.gatheringTarget, IID_ResourceSupply);
-						
-					// Check we can still reach and gather from the target
-					if (cmpSupply && this.CheckTargetRange(this.gatheringTarget, IID_ResourceGatherer) && this.CanGather(this.gatheringTarget) && cmpSupply.IsAvailable(this.entity))
+
+					if (cmpSupply && cmpSupply.IsAvailable(this.entity))
 					{
-						// Gather the resources:
-
-						var cmpResourceGatherer = Engine.QueryInterface(this.entity, IID_ResourceGatherer);
-
-						// Try to gather treasure
-						if (cmpResourceGatherer.TryInstantGather(this.gatheringTarget))
-							return;
-						
-						// If we've already got some resources but they're the wrong type,
-						// drop them first to ensure we're only ever carrying one type
-						if (cmpResourceGatherer.IsCarryingAnythingExcept(resourceType.generic))
-							cmpResourceGatherer.DropResources();
-
-						// Collect from the target
-						var status = cmpResourceGatherer.PerformGather(this.gatheringTarget);
-
-						// If we've collected as many resources as possible,
-						// return to the nearest dropsite
-						if (status.filled)
+						// Check we can still reach and gather from the target
+						if (this.CheckTargetRange(this.gatheringTarget, IID_ResourceGatherer) && this.CanGather(this.gatheringTarget))
 						{
-							var nearby = this.FindNearestDropsite(resourceType.generic);
-							if (nearby)
+							// Gather the resources:
+
+							var cmpResourceGatherer = Engine.QueryInterface(this.entity, IID_ResourceGatherer);
+
+							// Try to gather treasure
+							if (cmpResourceGatherer.TryInstantGather(this.gatheringTarget))
+								return;
+
+							// If we've already got some resources but they're the wrong type,
+							// drop them first to ensure we're only ever carrying one type
+							if (cmpResourceGatherer.IsCarryingAnythingExcept(resourceType.generic))
+								cmpResourceGatherer.DropResources();
+
+							// Collect from the target
+							var status = cmpResourceGatherer.PerformGather(this.gatheringTarget);
+
+							// If we've collected as many resources as possible,
+							// return to the nearest dropsite
+							if (status.filled)
 							{
-								// (Keep this Gather order on the stack so we'll
-								// continue gathering after returning)
-								this.PushOrderFront("ReturnResource", { "target": nearby, "force": false });
+								var nearby = this.FindNearestDropsite(resourceType.generic);
+								if (nearby)
+								{
+									// (Keep this Gather order on the stack so we'll
+									// continue gathering after returning)
+									this.PushOrderFront("ReturnResource", { "target": nearby, "force": false });
+									return;
+								}
+
+								// Oh no, couldn't find any drop sites. Give up on gathering.
+								this.FinishOrder();
 								return;
 							}
 
-							// Oh no, couldn't find any drop sites. Give up on gathering.
-							this.FinishOrder();
-							return;
+							// We can gather more from this target, do so in the next timer
+							if (!status.exhausted)
+								return;
 						}
-
-						// We can gather more from this target, do so in the next timer
-						if (!status.exhausted)
-							return;
-					}
-					else if (cmpSupply && cmpSupply.IsAvailable(this.entity))
-					{
-						// Try to follow the target
-						if (this.MoveToTargetRange(this.gatheringTarget, IID_ResourceGatherer))
+						else
 						{
-							this.SetNextState("APPROACHING");
-							return;
-						}
+							// Try to follow the target
+							if (this.MoveToTargetRange(this.gatheringTarget, IID_ResourceGatherer))
+							{
+								this.SetNextState("APPROACHING");
+								return;
+							}
 
-						// Can't reach the target, or it doesn't exist any more
+							// Can't reach the target, or it doesn't exist any more
 
-						// We want to carry on gathering resources in the same area as
-						// the old one. So try to get close to the old resource's
-						// last known position
+							// We want to carry on gathering resources in the same area as
+							// the old one. So try to get close to the old resource's
+							// last known position
 
-						var maxRange = 8; // get close but not too close
-						if (this.order.data.lastPos &&
-							this.MoveToPointRange(this.order.data.lastPos.x, this.order.data.lastPos.z,
-								0, maxRange))
-						{
-							this.SetNextState("APPROACHING");
-							return;
+							var maxRange = 8; // get close but not too close
+							if (this.order.data.lastPos &&
+								this.MoveToPointRange(this.order.data.lastPos.x, this.order.data.lastPos.z,
+									0, maxRange))
+							{
+								this.SetNextState("APPROACHING");
+								return;
+							}
 						}
 					}