diff --git a/ConverterApp/Properties/AssemblyInfo.cs b/ConverterApp/Properties/AssemblyInfo.cs
index 74225f9d..908ddd1a 100644
--- a/ConverterApp/Properties/AssemblyInfo.cs
+++ b/ConverterApp/Properties/AssemblyInfo.cs
@@ -31,5 +31,5 @@
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.15.7.0")]
-[assembly: AssemblyFileVersion("1.15.7.0")]
+[assembly: AssemblyVersion("1.15.8.0")]
+[assembly: AssemblyFileVersion("1.15.8.0")]
diff --git a/LSLib/LS/Common.cs b/LSLib/LS/Common.cs
index f8aa7593..1bd8d396 100644
--- a/LSLib/LS/Common.cs
+++ b/LSLib/LS/Common.cs
@@ -9,7 +9,7 @@ public static class Common
 
 		public const int MinorVersion = 15;
 
-		public const int PatchVersion = 7;
+		public const int PatchVersion = 8;
 
 		/// <summary>
 		/// Returns the version number of the LSLib library
diff --git a/LSLib/LS/Enums/Game.cs b/LSLib/LS/Enums/Game.cs
index 8beffe97..da43875f 100644
--- a/LSLib/LS/Enums/Game.cs
+++ b/LSLib/LS/Enums/Game.cs
@@ -35,7 +35,7 @@ public static FileVersion LSFVersion(this Game game)
             }
             else
             {
-                return FileVersion.VerBG3;
+                return FileVersion.VerExtendedHeader;
             }
         }
     }
diff --git a/LSLib/LS/LSFWriter.cs b/LSLib/LS/LSFWriter.cs
index 978037eb..a0e65188 100644
--- a/LSLib/LS/LSFWriter.cs
+++ b/LSLib/LS/LSFWriter.cs
@@ -30,11 +30,13 @@ public class LSFWriter
 
         private List<List<string>> StringHashMap;
         private bool ExtendedNodes = false;
+        private List<int> NextSiblingIndices;
 
         public LSFWriter(Stream stream, FileVersion version)
         {
             this.Stream = stream;
             this.Version = (uint) version;
+            this.ExtendedNodes = (this.Version >= (uint)FileVersion.VerExtendedNodes);
         }
 
         public void Write(Resource resource)
@@ -62,12 +64,18 @@ public void Write(Resource resource)
                 NextNodeIndex = 0;
                 NextAttributeIndex = 0;
                 NodeIndices = new Dictionary<Node, int>();
+                NextSiblingIndices = null;
                 StringHashMap = new List<List<string>>(StringHashMapSize);
                 while (StringHashMap.Count < StringHashMapSize)
                 {
                     StringHashMap.Add(new List<string>());
                 }
 
+                if (ExtendedNodes)
+                {
+                    ComputeSiblingIndices(resource);
+                }
+
                 WriteRegions(resource);
 
                 byte[] stringBuffer = null;
@@ -122,6 +130,8 @@ public void Write(Resource resource)
                 meta.Unknown3 = 0;
                 meta.Extended = ExtendedNodes ? 1u : 0u;
 
+                BinUtils.WriteStruct<Header>(Writer, ref header);
+
                 if (header.Version < (ulong)FileVersion.VerExtendedHeader)
                 {
                     BinUtils.WriteStruct<Metadata>(Writer, ref meta);
@@ -141,8 +151,51 @@ public void Write(Resource resource)
             }
         }
 
+        private int ComputeSiblingIndices(Node node)
+        {
+            int index = NextNodeIndex;
+            NextNodeIndex++;
+            NextSiblingIndices.Add(-1);
+
+            int lastSiblingIndex = -1;
+            foreach (var children in node.Children)
+            {
+                foreach (var child in children.Value)
+                {
+                    int childIndex = ComputeSiblingIndices(child);
+                    if (lastSiblingIndex != -1)
+                    {
+                        NextSiblingIndices[lastSiblingIndex] = childIndex;
+                    }
+
+                    lastSiblingIndex = childIndex;
+                }
+            }
+
+            return index;
+        }
+
+        private void ComputeSiblingIndices(Resource resource)
+        {
+            NextNodeIndex = 0;
+            NextSiblingIndices = new List<int>();
+
+            int lastRegionIndex = -1;
+            foreach (var region in resource.Regions)
+            {
+                int regionIndex = ComputeSiblingIndices(region.Value);
+                if (lastRegionIndex != -1)
+                {
+                    NextSiblingIndices[lastRegionIndex] = regionIndex;
+                }
+
+                lastRegionIndex = regionIndex;
+            }
+        }
+
         private void WriteRegions(Resource resource)
         {
+            NextNodeIndex = 0;
             foreach (var region in resource.Regions)
             {
                 if (Version >= (ulong) FileVersion.VerExtendedNodes
@@ -197,7 +250,7 @@ private void WriteNodeAttributesV3(Node node)
                 {
                     attributeInfo.NextAttributeIndex = NextAttributeIndex + 1;
                 }
-                attributeInfo.Offset = (UInt32)ValueStream.Position;
+                attributeInfo.Offset = lastOffset;
                 BinUtils.WriteStruct<AttributeEntryV3>(AttributeWriter, ref attributeInfo);
 
                 NextAttributeIndex++;
@@ -269,6 +322,9 @@ private void WriteNodeV3(Node node)
 
             nodeInfo.NameHashTableIndex = AddStaticString(node.Name);
 
+            // Assumes we calculated indices first using ComputeSiblingIndices()
+            nodeInfo.NextSiblingIndex = NextSiblingIndices[NextNodeIndex];
+
             if (node.Attributes.Count > 0)
             {
                 nodeInfo.FirstAttributeIndex = NextAttributeIndex;
@@ -279,9 +335,6 @@ private void WriteNodeV3(Node node)
                 nodeInfo.FirstAttributeIndex = -1;
             }
 
-            // FIXME!
-            throw new Exception("Writing uncompressed LSFv3 is not supported yet");
-            nodeInfo.NextSiblingIndex = -1;
             BinUtils.WriteStruct<NodeEntryV3>(NodeWriter, ref nodeInfo);
             NodeIndices[node] = NextNodeIndex;
             NextNodeIndex++;
diff --git a/LSLib/Properties/AssemblyInfo.cs b/LSLib/Properties/AssemblyInfo.cs
index 9697dc08..c5662fee 100644
--- a/LSLib/Properties/AssemblyInfo.cs
+++ b/LSLib/Properties/AssemblyInfo.cs
@@ -31,5 +31,5 @@
 // You can specify all the values or you can default the Build and Revision Numbers
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("1.15.7.0")]
-[assembly: AssemblyFileVersion("1.15.7.0")]
+[assembly: AssemblyVersion("1.15.8.0")]
+[assembly: AssemblyFileVersion("1.15.8.0")]