diff --git a/Aaru.Core/Devices/Dumping/CompactDisc/Data.cs b/Aaru.Core/Devices/Dumping/CompactDisc/Data.cs
index 228543659..bfe222e5c 100644
--- a/Aaru.Core/Devices/Dumping/CompactDisc/Data.cs
+++ b/Aaru.Core/Devices/Dumping/CompactDisc/Data.cs
@@ -86,7 +86,7 @@ namespace Aaru.Core.Devices.Dumping
                         bool read12, bool read16, bool readcd, int sectorsForOffset, uint subSize,
                         MmcSubchannel supportedSubchannel, bool supportsLongSectors, ref double totalDuration,
                         Track[] tracks, SubchannelLog subLog, MmcSubchannel desiredSubchannel,
-                        Dictionary<byte, string> isrcs, ref string mcn, ExtentsInt subchannelExtents)
+                        Dictionary<byte, string> isrcs, ref string mcn, HashSet<int> subchannelExtents)
         {
             ulong      sectorSpeedStart = 0;               // Used to calculate correct speed
             DateTime   timeSpeedStart   = DateTime.UtcNow; // Time of start for speed calculation
diff --git a/Aaru.Core/Devices/Dumping/CompactDisc/Dump.cs b/Aaru.Core/Devices/Dumping/CompactDisc/Dump.cs
index 09129e9bb..6548bee04 100644
--- a/Aaru.Core/Devices/Dumping/CompactDisc/Dump.cs
+++ b/Aaru.Core/Devices/Dumping/CompactDisc/Dump.cs
@@ -115,7 +115,7 @@ namespace Aaru.Core.Devices.Dumping
             bool                     bcdSubchannel     = false; // Subchannel positioning is in BCD
             Dictionary<byte, string> isrcs             = new Dictionary<byte, string>();
             string                   mcn               = null;
-            var                      subchannelExtents = new ExtentsInt();
+            HashSet<int>             subchannelExtents = new HashSet<int>();
 
             Dictionary<MediaTagType, byte[]> mediaTags = new Dictionary<MediaTagType, byte[]>(); // Media tags
 
@@ -852,7 +852,7 @@ namespace Aaru.Core.Devices.Dumping
             if(supportedSubchannel != MmcSubchannel.None &&
                desiredSubchannel   != MmcSubchannel.None)
             {
-                subchannelExtents = new ExtentsInt();
+                subchannelExtents = new HashSet<int>();
 
                 _resume.BadSubchannels ??= new List<int>();
 
@@ -860,7 +860,8 @@ namespace Aaru.Core.Devices.Dumping
                     subchannelExtents.Add(sub);
 
                 if(_resume.NextBlock < blocks)
-                    subchannelExtents.Add((int)_resume.NextBlock, (int)(blocks - 1));
+                    for(ulong i = _resume.NextBlock; i < blocks; i++)
+                        subchannelExtents.Add((int)i);
             }
 
             if(_resume.NextBlock > 0)
@@ -1106,18 +1107,7 @@ namespace Aaru.Core.Devices.Dumping
             currentTry.Extents = ExtentsConverter.ToMetadata(extents);
 
             _resume.BadSubchannels = new List<int>();
-
-            foreach(Tuple<int, int> extent in subchannelExtents.ToArray())
-            {
-                for(int sub = extent.Item1; sub <= extent.Item2; sub++)
-                {
-                    if(sub >= (int)_resume.NextBlock)
-                        continue;
-
-                    _resume.BadSubchannels.Add(sub);
-                }
-            }
-
+            _resume.BadSubchannels.AddRange(subchannelExtents);
             _resume.BadSubchannels.Sort();
 
             // TODO: Disc ID
diff --git a/Aaru.Core/Devices/Dumping/CompactDisc/Error.cs b/Aaru.Core/Devices/Dumping/CompactDisc/Error.cs
index 92a99fce4..97ff24af5 100644
--- a/Aaru.Core/Devices/Dumping/CompactDisc/Error.cs
+++ b/Aaru.Core/Devices/Dumping/CompactDisc/Error.cs
@@ -55,7 +55,7 @@ namespace Aaru.Core.Devices.Dumping
                              ExtentsULong extents, int offsetBytes, bool readcd, int sectorsForOffset, uint subSize,
                              MmcSubchannel supportedSubchannel, ref double totalDuration, SubchannelLog subLog,
                              MmcSubchannel desiredSubchannel, Track[] tracks, Dictionary<byte, string> isrcs,
-                             ref string mcn, ExtentsInt subchannelExtents)
+                             ref string mcn, HashSet<int> subchannelExtents)
         {
             bool              sense  = true;     // Sense indicator
             byte[]            cmdBuf = null;     // Data buffer
@@ -447,7 +447,7 @@ namespace Aaru.Core.Devices.Dumping
 
         void RetrySubchannel(bool readcd, uint subSize, MmcSubchannel supportedSubchannel, ref double totalDuration,
                              SubchannelLog subLog, MmcSubchannel desiredSubchannel, Track[] tracks,
-                             Dictionary<byte, string> isrcs, ref string mcn, ExtentsInt subchannelExtents)
+                             Dictionary<byte, string> isrcs, ref string mcn, HashSet<int> subchannelExtents)
         {
             bool              sense  = true;     // Sense indicator
             byte[]            cmdBuf = null;     // Data buffer
@@ -495,18 +495,7 @@ namespace Aaru.Core.Devices.Dumping
             cdRepeatRetry:
 
             _resume.BadSubchannels = new List<int>();
-
-            foreach(Tuple<int, int> extent in subchannelExtents.ToArray())
-            {
-                for(int sub = extent.Item1; sub <= extent.Item2; sub++)
-                {
-                    if(sub >= (int)_resume.NextBlock)
-                        continue;
-
-                    _resume.BadSubchannels.Add(sub);
-                }
-            }
-
+            _resume.BadSubchannels.AddRange(subchannelExtents);
             _resume.BadSubchannels.Sort();
 
             if(!forward)
diff --git a/Aaru.Core/Devices/Dumping/CompactDisc/LeadOuts.cs b/Aaru.Core/Devices/Dumping/CompactDisc/LeadOuts.cs
index 186457e4f..b82061d90 100644
--- a/Aaru.Core/Devices/Dumping/CompactDisc/LeadOuts.cs
+++ b/Aaru.Core/Devices/Dumping/CompactDisc/LeadOuts.cs
@@ -75,7 +75,7 @@ namespace Aaru.Core.Devices.Dumping
                             bool read6, bool read10, bool read12, bool read16, bool readcd,
                             MmcSubchannel supportedSubchannel, uint subSize, ref double totalDuration,
                             SubchannelLog subLog, MmcSubchannel desiredSubchannel, Dictionary<byte, string> isrcs,
-                            ref string mcn, Track[] tracks, ExtentsInt subchannelExtents)
+                            ref string mcn, Track[] tracks, HashSet<int> subchannelExtents)
         {
             byte[]     cmdBuf     = null; // Data buffer
             const uint sectorSize = 2352; // Full sector size
@@ -239,7 +239,7 @@ namespace Aaru.Core.Devices.Dumping
                              bool read6, bool read10, bool read12, bool read16, bool readcd,
                              MmcSubchannel supportedSubchannel, uint subSize, ref double totalDuration,
                              SubchannelLog subLog, MmcSubchannel desiredSubchannel, Dictionary<byte, string> isrcs,
-                             ref string mcn, Track[] tracks, ExtentsInt subchannelExtents)
+                             ref string mcn, Track[] tracks, HashSet<int> subchannelExtents)
         {
             byte[]     cmdBuf     = null; // Data buffer
             const uint sectorSize = 2352; // Full sector size
diff --git a/Aaru.Core/Devices/Dumping/CompactDisc/Subchannel.cs b/Aaru.Core/Devices/Dumping/CompactDisc/Subchannel.cs
index 9061600fb..3d6c3f7d8 100644
--- a/Aaru.Core/Devices/Dumping/CompactDisc/Subchannel.cs
+++ b/Aaru.Core/Devices/Dumping/CompactDisc/Subchannel.cs
@@ -34,7 +34,6 @@ using System;
 using System.Collections.Generic;
 using Aaru.Checksums;
 using Aaru.CommonTypes.Enums;
-using Aaru.CommonTypes.Extents;
 using Aaru.CommonTypes.Structs;
 using Aaru.Core.Logging;
 using Aaru.Decoders.CD;
@@ -72,7 +71,7 @@ namespace Aaru.Core.Devices.Dumping
         bool WriteSubchannelToImage(MmcSubchannel supportedSubchannel, MmcSubchannel desiredSubchannel, byte[] sub,
                                     ulong sectorAddress, uint length, SubchannelLog subLog,
                                     Dictionary<byte, string> isrcs, byte currentTrack, ref string mcn, Track[] tracks,
-                                    ExtentsInt subchannelExtents)
+                                    HashSet<int> subchannelExtents)
         {
             if(supportedSubchannel == MmcSubchannel.Q16)
                 sub = Subchannel.ConvertQToRaw(sub);
diff --git a/Aaru.Core/Devices/Dumping/CompactDisc/Trim.cs b/Aaru.Core/Devices/Dumping/CompactDisc/Trim.cs
index 1f6188151..5323cdc73 100644
--- a/Aaru.Core/Devices/Dumping/CompactDisc/Trim.cs
+++ b/Aaru.Core/Devices/Dumping/CompactDisc/Trim.cs
@@ -53,7 +53,7 @@ namespace Aaru.Core.Devices.Dumping
                             bool read16, bool readcd, int sectorsForOffset, uint subSize,
                             MmcSubchannel supportedSubchannel, bool supportsLongSectors, ref double totalDuration,
                             SubchannelLog subLog, MmcSubchannel desiredSubchannel, Track[] tracks,
-                            Dictionary<byte, string> isrcs, ref string mcn, ExtentsInt subchannelExtents)
+                            Dictionary<byte, string> isrcs, ref string mcn, HashSet<int> subchannelExtents)
         {
             DateTime          start;
             DateTime          end;