diff --git a/OpenRA.Mods.Common/Pathfinder/HierarchicalPathFinder.cs b/OpenRA.Mods.Common/Pathfinder/HierarchicalPathFinder.cs
index d0333449d7..ba066942cc 100644
--- a/OpenRA.Mods.Common/Pathfinder/HierarchicalPathFinder.cs
+++ b/OpenRA.Mods.Common/Pathfinder/HierarchicalPathFinder.cs
@@ -629,9 +629,19 @@ namespace OpenRA.Mods.Common.Pathfinder
 				var sourcesWithPathableNodes = new List<CPos>(sourcesWithReachableNodes.Count);
 				foreach (var source in sourcesWithReachableNodes)
 				{
-					reverseAbstractSearch.TargetPredicate = cell => cell == source;
-					if (reverseAbstractSearch.ExpandToTarget())
-						sourcesWithPathableNodes.Add(source);
+					// Check if we have already found a route to this node before we attempt to expand the search.
+					var sourceStatus = reverseAbstractSearch.Graph[source];
+					if (sourceStatus.Status == CellStatus.Closed)
+					{
+						if (sourceStatus.CostSoFar != PathGraph.PathCostForInvalidPath)
+							sourcesWithPathableNodes.Add(source);
+					}
+					else
+					{
+						reverseAbstractSearch.TargetPredicate = cell => cell == source;
+						if (reverseAbstractSearch.ExpandToTarget())
+							sourcesWithPathableNodes.Add(source);
+					}
 				}
 
 				if (sourcesWithPathableNodes.Count == 0)
@@ -900,8 +910,8 @@ namespace OpenRA.Mods.Common.Pathfinder
 				var abstractCell = gridInfo.AbstractCellForLocalCell(cell).Value;
 				var info = graph[abstractCell];
 
-				// Expand the abstract search if we have not visited the abstract cell.
-				if (info.Status == CellStatus.Unvisited)
+				// Expand the abstract search only if we have yet to get a route to the abstract cell.
+				if (info.Status != CellStatus.Closed)
 				{
 					abstractSearch.TargetPredicate = c => c == abstractCell;
 					if (!abstractSearch.ExpandToTarget())
diff --git a/OpenRA.Mods.Common/Pathfinder/PathSearch.cs b/OpenRA.Mods.Common/Pathfinder/PathSearch.cs
index e8459b928b..e127192856 100644
--- a/OpenRA.Mods.Common/Pathfinder/PathSearch.cs
+++ b/OpenRA.Mods.Common/Pathfinder/PathSearch.cs
@@ -241,6 +241,11 @@ namespace OpenRA.Mods.Common.Pathfinder
 		/// <summary>
 		/// Expands the path search until a path is found, and returns whether a path is found successfully.
 		/// </summary>
+		/// <remarks>
+		/// If the path search has previously been expanded it will only return true if a path can be found during
+		/// *this* expansion of the search. If the search was expanded previously and the target is already
+		/// <see cref="CellStatus.Closed"/> then this method will return false.
+		/// </remarks>
 		public bool ExpandToTarget()
 		{
 			while (CanExpand())