diff --git a/SabreTools.Serialization/Models/ISO9660/DirectoryRecord.cs b/SabreTools.Serialization/Models/ISO9660/DirectoryRecord.cs
index c43d84cc..3a3afe90 100644
--- a/SabreTools.Serialization/Models/ISO9660/DirectoryRecord.cs
+++ b/SabreTools.Serialization/Models/ISO9660/DirectoryRecord.cs
@@ -28,7 +28,7 @@ namespace SabreTools.Data.Models.ISO9660
         /// <summary>
         /// Number of bytes allocated to this extent (not including extended attribute record length)
         /// </summary>
-        public BothInt32 ExtentLength { get; set; } = 0;
+        public BothUInt32 ExtentLength { get; set; } = 0;
 
         /// <summary>
         /// Datetime of recording for the Directory Record
diff --git a/SabreTools.Serialization/Readers/ISO9660.cs b/SabreTools.Serialization/Readers/ISO9660.cs
index 1a48b6cb..72a71147 100644
--- a/SabreTools.Serialization/Readers/ISO9660.cs
+++ b/SabreTools.Serialization/Readers/ISO9660.cs
@@ -635,7 +635,7 @@ namespace SabreTools.Serialization.Readers
 
             // Use provided extent endinanness
             int extentLocation = bigEndian ? dr.ExtentLocation.BigEndian : dr.ExtentLocation.LittleEndian;
-            int extentLength = bigEndian ? dr.ExtentLength.BigEndian : dr.ExtentLength.LittleEndian;
+            uint extentLength = bigEndian ? dr.ExtentLength.BigEndian : dr.ExtentLength.LittleEndian;
             long extentOffset = (long)extentLocation * (long)blockLength;
             long extentFinal = extentOffset + (long)extentLength;
 
@@ -668,7 +668,7 @@ namespace SabreTools.Serialization.Readers
 
                 // Read all directory records in this directory
                 var records = new List<DirectoryRecord>();
-                int pos = 0;
+                uint pos = 0;
                 while (pos < extentLength)
                 {
                     // Peek next byte to check whether the next record length is not greater than the end of the dir extent
@@ -677,8 +677,8 @@ namespace SabreTools.Serialization.Readers
                     // If record length of 0x00, next record begins in next sector
                     if (recordLength == 0)
                     {
-                        int paddingLength = sectorLength - (pos % sectorLength);
-                        pos += paddingLength;
+                        int paddingLength = (int)((uint)sectorLength - (pos % (uint)sectorLength));
+                        pos += (uint)paddingLength;
                         _ = data.ReadBytes(paddingLength);
 
                         // Finish parsing records if end reached
@@ -786,7 +786,7 @@ namespace SabreTools.Serialization.Readers
             obj.DirectoryRecordLength = data.ReadByteValue();
             obj.ExtendedAttributeRecordLength = data.ReadByteValue();
             obj.ExtentLocation = data.ReadInt32BothEndian();
-            obj.ExtentLength = data.ReadInt32BothEndian();
+            obj.ExtentLength = data.ReadUInt32BothEndian();
 
             obj.RecordingDateTime = ParseDirectoryRecordDateTime(data);
 
diff --git a/SabreTools.Serialization/Wrappers/ISO9660.Extraction.cs b/SabreTools.Serialization/Wrappers/ISO9660.Extraction.cs
index 964110e0..7a150ba9 100644
--- a/SabreTools.Serialization/Wrappers/ISO9660.Extraction.cs
+++ b/SabreTools.Serialization/Wrappers/ISO9660.Extraction.cs
@@ -15,7 +15,7 @@ namespace SabreTools.Serialization.Wrappers
         /// <summary>
         /// List of extracted files by their sector offset
         /// </summary>
-        private readonly Dictionary<int, int> extractedFiles = [];
+        private readonly Dictionary<int, uint> extractedFiles = [];
 
         /// <summary>
         /// List of multi-extent files written, by their FileIdentifier
@@ -188,21 +188,21 @@ namespace SabreTools.Serialization.Wrappers
             if (!multiExtent && (File.Exists(filepath) || Directory.Exists(filepath)))
             {
                 // If it's the last extent of a multi-extent file, continue to append
-                if (multiExtentFiles.Exists(item => item.EqualsExactly(dr.FileIdentifier)))
+                if (!multiExtentFiles.Exists(item => item.EqualsExactly(dr.FileIdentifier)))
                 {
                     if (includeDebug) Console.WriteLine($"File/Folder already exists, cannot extract: {filename}");
                     return false;
                 }
             }
 
-            const int chunkSize = 2048 * 1024;
+            const uint chunkSize = 2048 * 1024;
             lock (_dataSourceLock)
             {
                 long fileOffset = ((long)dr.ExtentLocation + dr.ExtendedAttributeRecordLength) * blockLength;
                 _dataSource.SeekIfPossible(fileOffset, SeekOrigin.Begin);
 
                 // Get the length, and make sure it won't EOF
-                int length = dr.ExtentLength;
+                uint length = dr.ExtentLength;
                 if (length > _dataSource.Length - _dataSource.Position)
                     return false;
 
@@ -211,13 +211,13 @@ namespace SabreTools.Serialization.Wrappers
                 using var fs = File.Open(filepath, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
                 while (length > 0)
                 {
-                    int bytesToRead = Math.Min(length, chunkSize);
+                    int bytesToRead = (int)Math.Min(length, chunkSize);
 
                     byte[] buffer = _dataSource.ReadBytes(bytesToRead);
                     fs.Write(buffer, 0, bytesToRead);
                     fs.Flush();
 
-                    length -= bytesToRead;
+                    length -= (uint)bytesToRead;
                 }
 
                 // Mark the file as extracted