diff --git a/OpenRA.Mods.Common/Activities/FindAndDeliverResources.cs b/OpenRA.Mods.Common/Activities/FindAndDeliverResources.cs
index de427fcfdc..6141e1199f 100644
--- a/OpenRA.Mods.Common/Activities/FindAndDeliverResources.cs
+++ b/OpenRA.Mods.Common/Activities/FindAndDeliverResources.cs
@@ -180,7 +180,8 @@ namespace OpenRA.Mods.Common.Activities
 
 			var searchRadiusSquared = searchRadius * searchRadius;
 
-			var procPos = procLoc.HasValue ? (WPos?)self.World.Map.CenterOfCell(procLoc.Value) : null;
+			var map = self.World.Map;
+			var procPos = procLoc.HasValue ? (WPos?)map.CenterOfCell(procLoc.Value) : null;
 			var harvPos = self.CenterPosition;
 
 			// Find any harvestable resources:
@@ -190,25 +191,28 @@ namespace OpenRA.Mods.Common.Activities
 				.WithCustomCost(loc =>
 				{
 					if ((loc - searchFromLoc).LengthSquared > searchRadiusSquared)
-						return int.MaxValue;
+						return PathGraph.CostForInvalidCell;
 
 					// Add a cost modifier to harvestable cells to prefer resources that are closer to the refinery.
 					// This reduces the tendancy for harvesters to move in straight lines
 					if (procPos.HasValue && harvInfo.ResourceRefineryDirectionPenalty > 0 && harv.CanHarvestCell(self, loc))
 					{
-						var pos = self.World.Map.CenterOfCell(loc);
+						var pos = map.CenterOfCell(loc);
 
 						// Calculate harv-cell-refinery angle (cosine rule)
-						var a = harvPos - procPos.Value;
 						var b = pos - procPos.Value;
-						var c = pos - harvPos;
 
-						if (b != WVec.Zero && c != WVec.Zero)
+						if (b != WVec.Zero)
 						{
-							var cosA = (int)(512 * (b.LengthSquared + c.LengthSquared - a.LengthSquared) / b.Length / c.Length);
+							var c = pos - harvPos;
+							if (c != WVec.Zero)
+							{
+								var a = harvPos - procPos.Value;
+								var cosA = (int)(512 * (b.LengthSquared + c.LengthSquared - a.LengthSquared) / b.Length / c.Length);
 
-							// Cost modifier varies between 0 and ResourceRefineryDirectionPenalty
-							return Math.Abs(harvInfo.ResourceRefineryDirectionPenalty / 2) + harvInfo.ResourceRefineryDirectionPenalty * cosA / 2048;
+								// Cost modifier varies between 0 and ResourceRefineryDirectionPenalty
+								return Math.Abs(harvInfo.ResourceRefineryDirectionPenalty / 2) + harvInfo.ResourceRefineryDirectionPenalty * cosA / 2048;
+							}
 						}
 					}
 
diff --git a/OpenRA.Mods.Common/Traits/World/PathFinder.cs b/OpenRA.Mods.Common/Traits/World/PathFinder.cs
index 1f86f21d1c..65a890be09 100644
--- a/OpenRA.Mods.Common/Traits/World/PathFinder.cs
+++ b/OpenRA.Mods.Common/Traits/World/PathFinder.cs
@@ -110,11 +110,14 @@ namespace OpenRA.Mods.Common.Traits
 			// Correct for SubCell offset
 			target -= world.Map.Grid.OffsetOfSubCell(srcSub);
 
+			var rangeLengthSquared = range.LengthSquared;
+			var map = world.Map;
+
 			// Select only the tiles that are within range from the requested SubCell
 			// This assumes that the SubCell does not change during the path traversal
-			var tilesInRange = world.Map.FindTilesInCircle(targetCell, range.Length / 1024 + 1)
-				.Where(t => (world.Map.CenterOfCell(t) - target).LengthSquared <= range.LengthSquared
-							&& mobile.Info.CanEnterCell(self.World, self, t));
+			var tilesInRange = map.FindTilesInCircle(targetCell, range.Length / 1024 + 1)
+				.Where(t => (map.CenterOfCell(t) - target).LengthSquared <= rangeLengthSquared
+							&& mobile.Info.CanEnterCell(world, self, t));
 
 			// See if there is any cell within range that does not involve a cross-domain request
 			// Really, we only need to check the circle perimeter, but it's not clear that would be a performance win