diff --git a/ArcFormats/LunaSoft/ArcPAC.cs b/ArcFormats/LunaSoft/ArcPAC.cs
index bfad8871..e6bc68ed 100644
--- a/ArcFormats/LunaSoft/ArcPAC.cs
+++ b/ArcFormats/LunaSoft/ArcPAC.cs
@@ -45,23 +45,44 @@ namespace GameRes.Formats.LunaSoft
             if (!IsSaneCount (count))
                 return null;
             long base_offset = file.View.ReadUInt32 (8);
-
-            uint current_offset = 0x10;
             var dir = new List<Entry> (count);
+            if (!ReadIndex (file, dir, count, base_offset) &&
+                !ReadIndex (file, dir, count, base_offset, true))
+                return null;
+            return new ArcFile (file, this, dir);
+        }
+
+        bool ReadIndex (ArcView file, List<Entry> dir, int count, long base_offset, bool long_offsets = false)
+        {
+            Func<uint, long> read_offset;
+            uint size_pos;
+            if (long_offsets)
+            {
+                read_offset = idx_off => file.View.ReadInt64 (idx_off);
+                size_pos = 0x108;
+            }
+            else
+            {
+                read_offset = idx_off => file.View.ReadUInt32 (idx_off);
+                size_pos = 0x104;
+            }
+            dir.Clear();
+            uint current_offset = 0x10;
             for (int i = 0; i < count; ++i)
             {
-                uint name_length = file.View.ReadUInt32 (current_offset+0x108);
+                uint name_length = file.View.ReadUInt32 (current_offset+size_pos+4);
+                if (name_length > 0x100 || 0 == name_length)
+                    return false;
                 var name = file.View.ReadString (current_offset, name_length);
-                var entry = FormatCatalog.Instance.Create<Entry> (name);
-                current_offset += 0x100;
-                entry.Offset = base_offset + file.View.ReadUInt32 (current_offset);
-                entry.Size = file.View.ReadUInt32 (current_offset+4);
+                var entry = Create<Entry> (name);
+                entry.Offset = base_offset + read_offset (current_offset+0x100);
+                entry.Size = file.View.ReadUInt32 (current_offset+size_pos);
                 if (!entry.CheckPlacement (file.MaxOffset))
-                    return null;
+                    return false;
                 dir.Add (entry);
-                current_offset += 0xC;
+                current_offset += size_pos+8;
             }
-            return new ArcFile (file, this, dir);
+            return true;
         }
     }
 }