diff --git a/TombLib/TombLib/LevelData/Compilers/Rooms.cs b/TombLib/TombLib/LevelData/Compilers/Rooms.cs
index 1224b8a2d..0539d09cf 100644
--- a/TombLib/TombLib/LevelData/Compilers/Rooms.cs
+++ b/TombLib/TombLib/LevelData/Compilers/Rooms.cs
@@ -667,7 +667,8 @@ private tr_room BuildRoom(Room room)
                                 },
                                 Lighting1 = 0,
                                 Lighting2 = 0,
-                                Attributes = 0
+                                Attributes = 0,
+                                Normal = normal
                             };
 
                             // Pack the light according to chosen lighting model
@@ -709,7 +710,12 @@ private tr_room BuildRoom(Room room)
                             }
                             else
                             {
-                                existingIndex = roomVertices.IndexOf(v => v.Position == trVertex.Position && v.Color == trVertex.Color);
+                                existingIndex = roomVertices.IndexOf(v =>
+                                    v.Position == trVertex.Position &&
+                                    v.Lighting1 == trVertex.Lighting1 &&
+                                    v.Attributes == trVertex.Attributes &&
+                                    v.Lighting2 == trVertex.Lighting2 &&
+                                    v.Normal == trVertex.Normal);
                                 if (existingIndex == -1)
                                 {
                                     existingIndex = roomVertices.Count;
diff --git a/TombLib/TombLib/LevelData/Compilers/TombEngine/Rooms.cs b/TombLib/TombLib/LevelData/Compilers/TombEngine/Rooms.cs
index 86ce048b3..282723570 100644
--- a/TombLib/TombLib/LevelData/Compilers/TombEngine/Rooms.cs
+++ b/TombLib/TombLib/LevelData/Compilers/TombEngine/Rooms.cs
@@ -644,6 +644,7 @@ private TombEngineRoom BuildRoom(Room room)
 											var span = CollectionsMarshal.AsSpan(roomVertices);
                                             for (int i = 0; (uint)i < (uint)span.Length; i++)
                                                 if (span[i].Position == trVertex.Position &&
+                                                    span[i].Normal == trVertex.Normal &&
                                                     span[i].Color == trVertex.Color &&
                                                     span[i].DoubleSided == trVertex.DoubleSided)
                                                 {
diff --git a/TombLib/TombLib/LevelData/Room.cs b/TombLib/TombLib/LevelData/Room.cs
index 9cc2ffc08..d6380acb1 100644
--- a/TombLib/TombLib/LevelData/Room.cs
+++ b/TombLib/TombLib/LevelData/Room.cs
@@ -1870,6 +1870,8 @@ public void GetGeometryStatistics(out int vertices, out int faces)
 
                         // Apply the transform to the vertex
                         var position = MathC.HomogenousTransform(vertex.Position, worldTransform);
+                        var normal = MathC.HomogenousTransform(vertex.Normal, normalTransform);
+                        normal = Vector3.Normalize(normal);
                         var trVertex = new tr_room_vertex
                         {
                             Position = new tr_vertex
@@ -1880,7 +1882,8 @@ public void GetGeometryStatistics(out int vertices, out int faces)
                             },
                             Lighting1 = 0,
                             Lighting2 = 0,
-                            Attributes = 0
+                            Attributes = 0,
+                            Normal = normal
                         };
 
                         // HACK: Find a vertex with same coordinates and merge with it.
@@ -1896,7 +1899,12 @@ public void GetGeometryStatistics(out int vertices, out int faces)
                         }
                         else
                         {
-                            existingIndex = roomVertices.IndexOf(v => v.Position == trVertex.Position && v.Color == trVertex.Color);
+                            existingIndex = roomVertices.IndexOf(v =>
+                                v.Position == trVertex.Position &&
+                                v.Lighting1 == trVertex.Lighting1 &&
+                                v.Attributes == trVertex.Attributes &&
+                                v.Lighting2 == trVertex.Lighting2 &&
+                                v.Normal == trVertex.Normal);
                             if (existingIndex == -1)
                             {
                                 existingIndex = roomVertices.Count;