diff --git a/Assets/AstarPathfindingProject/Modifiers/RaycastModifier.cs b/Assets/AstarPathfindingProject/Modifiers/RaycastModifier.cs
index 7e0c5157..518bbb0a 100644
--- a/Assets/AstarPathfindingProject/Modifiers/RaycastModifier.cs
+++ b/Assets/AstarPathfindingProject/Modifiers/RaycastModifier.cs
@@ -142,6 +142,19 @@ namespace Pathfinding {
            bool canBeOriginalNodes = points.Count == p.path.Count;
            int startIndex = 0;

+           // Build an array of groups for the nodes/points list.
+           // A sequence of elements will have the same value if their
+           // corresponding points have roughly the same y coordinate
+           int[] nodeGroup = ArrayPool<int>.Claim(points.Count);
+           nodeGroup[0] = 0;
+           for (int i = 1; i < points.Count; i++) {
+               if (Mathf.Abs(points[i].y - points[i-1].y) < 0.01f) {
+                   nodeGroup[i] = nodeGroup[i-1];
+               } else {
+                   nodeGroup[i] = nodeGroup[i-1]+1;
+               }
+           }
+
            while (startIndex < points.Count) {
                Vector3 start = points[startIndex];
                var startNode = canBeOriginalNodes && points[startIndex] == (Vector3)p.path[startIndex].position ? p.path[startIndex] : null;
@@ -157,7 +170,7 @@ namespace Pathfinding {
                    }
                    Vector3 end = points[endIndex];
                    var endNode = canBeOriginalNodes && end == (Vector3)p.path[endIndex].position ? p.path[endIndex] : null;
-                   if (!ValidateLine(startNode, endNode, start, end)) break;
+                   if (!ValidateLine(startNode, endNode, start, end) && nodeGroup[endIndex] == nodeGroup[startIndex]) break;
                    mn = mx;
                    mx *= 2;
                }
@@ -168,7 +181,7 @@ namespace Pathfinding {
                    Vector3 end = points[endIndex];
                    var endNode = canBeOriginalNodes && end == (Vector3)p.path[endIndex].position ? p.path[endIndex] : null;

-                   if (ValidateLine(startNode, endNode, start, end)) {
+                   if (ValidateLine(startNode, endNode, start, end) && nodeGroup[endIndex] == nodeGroup[startIndex]) {
                        mn = mid;
                    } else {
                        mx = mid;
@@ -177,6 +190,7 @@ namespace Pathfinding {
                startIndex += mn;
            }

+           ArrayPool<int>.Release(ref nodeGroup);
            Memory.Swap(ref buffer, ref points);
            buffer.ClearFast();
            return points;