diff --git a/server/gameserver/glmhelper.cc b/server/gameserver/glmhelper.cc
index 77a726bc..b2cdea44 100644
--- a/server/gameserver/glmhelper.cc
+++ b/server/gameserver/glmhelper.cc
@@ -64,3 +64,10 @@ float GlmHelper::CalcAngle(const glm::vec3& v1, const glm::vec3& v2)
     #endif
     return angle / 3.1415926f;
 }
+
+void GlmHelper::FillVert(const glm::vec3& v, float* vert)
+{
+    vert[0] = v.x;
+    vert[1] = v.y;
+    vert[2] = v.z;
+}
diff --git a/server/gameserver/glmhelper.h b/server/gameserver/glmhelper.h
index 5fd82b36..4a799da6 100644
--- a/server/gameserver/glmhelper.h
+++ b/server/gameserver/glmhelper.h
@@ -15,4 +15,6 @@ class GlmHelper
 
     static float CalcAngle(const glm::vec3& v1, const glm::vec3& v2);
 
+    static void FillVert(const glm::vec3& v, float* vert);
+
 };
diff --git a/server/gameserver/mapservice.cc b/server/gameserver/mapservice.cc
index 6de7a860..c8403109 100644
--- a/server/gameserver/mapservice.cc
+++ b/server/gameserver/mapservice.cc
@@ -3,6 +3,8 @@
 #include <math.h>
 #include <memory.h>
 
+#include "DetourCommon.h"
+
 #include "mapservice.h"
 #include "entity.h"
 #include "roomobstacle.h"
@@ -128,13 +130,41 @@ void MapService::AddTriangle(mc::Triangle* tri)
         if (max_grid_y >= map_height_) {
             max_grid_y = map_height_ - 1;
         }
+        float tri_verts[3 * 3];
+        float aabb_verts[3 * 4];
+        {
+            GlmHelper::FillVert(tri->vert0, tri_verts + 3 * 0);
+            GlmHelper::FillVert(tri->vert1, tri_verts + 3 * 1);
+            GlmHelper::FillVert(tri->vert2, tri_verts + 3 * 2);
+        }
         for (int x = min_grid_x; x <= max_grid_x; ++x) {
             for (int y = min_grid_y; y <= max_grid_y; ++y) {
-                int grid_id = x  + y * map_width_;
-                list_head* head = &map_cells_[grid_id];
-                CellNode* node = new CellNode();
-                node->tri = tri;
-                list_add_tail(&node->entry, head);
+                float world_x = x * cell_width_;
+                float world_y = y * cell_width_;
+                {
+                    aabb_verts[0] = world_x;
+                    aabb_verts[1] = 0;
+                    aabb_verts[2] = world_y;
+
+                    aabb_verts[3] = world_x + cell_width_;
+                    aabb_verts[4] = 0;
+                    aabb_verts[5] = world_y;
+
+                    aabb_verts[6] = world_x + cell_width_;
+                    aabb_verts[7] = 0;
+                    aabb_verts[8] = world_y + cell_width_;
+
+                    aabb_verts[9] = world_x;
+                    aabb_verts[10] = 0;
+                    aabb_verts[11] = world_y + cell_width_;
+                }
+                if (dtOverlapPolyPoly2D(tri_verts, 3, aabb_verts, 4)) {
+                    int grid_id = x  + y * map_width_;
+                    list_head* head = &map_cells_[grid_id];
+                    CellNode* node = new CellNode();
+                    node->tri = tri;
+                    list_add_tail(&node->entry, head);
+                }
             }
         }
     }