diff --git a/SabreTools.Serialization/Models/PIC/DiscInformation.cs b/SabreTools.Serialization/Models/PIC/DiscInformation.cs
index d5893ade..92a65edf 100644
--- a/SabreTools.Serialization/Models/PIC/DiscInformation.cs
+++ b/SabreTools.Serialization/Models/PIC/DiscInformation.cs
@@ -29,6 +29,6 @@
         /// <summary>
         /// Disc information and emergency brake units
         /// </summary>
-        public DiscInformationUnit[]? Units { get; set; }
+        public DiscInformationUnit[] Units { get; set; }
     }
 }
diff --git a/SabreTools.Serialization/Models/PIC/DiscInformationUnit.cs b/SabreTools.Serialization/Models/PIC/DiscInformationUnit.cs
index b19fc415..8e235adf 100644
--- a/SabreTools.Serialization/Models/PIC/DiscInformationUnit.cs
+++ b/SabreTools.Serialization/Models/PIC/DiscInformationUnit.cs
@@ -7,12 +7,12 @@
         /// <summary>
         /// Unit header
         /// </summary>
-        public DiscInformationUnitHeader? Header { get; set; }
+        public DiscInformationUnitHeader Header { get; set; }
 
         /// <summary>
         /// Unit body
         /// </summary>
-        public DiscInformationUnitBody? Body { get; set; }
+        public DiscInformationUnitBody Body { get; set; }
 
         /// <summary>
         /// Unit trailer (BD-R/RE only)
diff --git a/SabreTools.Serialization/Models/PIC/DiscInformationUnitBody.cs b/SabreTools.Serialization/Models/PIC/DiscInformationUnitBody.cs
index a06a63f9..534d2de4 100644
--- a/SabreTools.Serialization/Models/PIC/DiscInformationUnitBody.cs
+++ b/SabreTools.Serialization/Models/PIC/DiscInformationUnitBody.cs
@@ -8,7 +8,7 @@ namespace SabreTools.Data.Models.PIC
         /// <summary>
         /// Disc Type Identifier
         /// </summary>
-        public string? DiscTypeIdentifier { get; set; }
+        public string DiscTypeIdentifier { get; set; }
 
         /// <summary>
         /// Disc Size/Class/Version
diff --git a/SabreTools.Serialization/Models/PIC/DiscInformationUnitHeader.cs b/SabreTools.Serialization/Models/PIC/DiscInformationUnitHeader.cs
index 227e72ed..696ace59 100644
--- a/SabreTools.Serialization/Models/PIC/DiscInformationUnitHeader.cs
+++ b/SabreTools.Serialization/Models/PIC/DiscInformationUnitHeader.cs
@@ -12,7 +12,7 @@ namespace SabreTools.Data.Models.PIC
         /// Emergency Brake Identifier "EB"
         /// </summary>
         [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 2)]
-        public string? DiscInformationIdentifier;
+        public string DiscInformationIdentifier;
 
         /// <summary>
         /// Disc Information Format
diff --git a/SabreTools.Serialization/Wrappers/PIC.Printing.cs b/SabreTools.Serialization/Wrappers/PIC.Printing.cs
index b77c828f..d8b31cdd 100644
--- a/SabreTools.Serialization/Wrappers/PIC.Printing.cs
+++ b/SabreTools.Serialization/Wrappers/PIC.Printing.cs
@@ -24,11 +24,11 @@ namespace SabreTools.Serialization.Wrappers
             Print(builder, Model.Units);
         }
 
-        private static void Print(StringBuilder builder, DiscInformationUnit[]? entries)
+        private static void Print(StringBuilder builder, DiscInformationUnit[] entries)
         {
             builder.AppendLine("  Disc Information Units:");
             builder.AppendLine("  -------------------------");
-            if (entries == null || entries.Length == 0)
+            if (entries.Length == 0)
             {
                 builder.AppendLine("  No disc information units");
                 builder.AppendLine();
@@ -40,34 +40,19 @@ namespace SabreTools.Serialization.Wrappers
                 var entry = entries[i];
 
                 builder.AppendLine($"  Disc Information Unit {i}");
-                if (entry.Header == null)
-                {
-                    builder.AppendLine("    No header");
-                }
-                else
-                {
-                    var header = entry.Header;
 
-                    builder.AppendLine(header.DiscInformationIdentifier, "    Disc information identifier");
-                    builder.AppendLine(header.DiscInformationFormat, "    Disc information format");
-                    builder.AppendLine(header.Reserved0, "    Reserved");
-                    builder.AppendLine(header.SequenceNumber, "    Sequence number");
-                    builder.AppendLine(header.BytesInUse, "    Bytes in use");
-                    builder.AppendLine(header.Reserved1, "    Reserved");
-                }
+                var header = entry.Header;
+                builder.AppendLine(header.DiscInformationIdentifier, "    Disc information identifier");
+                builder.AppendLine(header.DiscInformationFormat, "    Disc information format");
+                builder.AppendLine(header.Reserved0, "    Reserved");
+                builder.AppendLine(header.SequenceNumber, "    Sequence number");
+                builder.AppendLine(header.BytesInUse, "    Bytes in use");
+                builder.AppendLine(header.Reserved1, "    Reserved");
 
-                if (entry.Body == null)
-                {
-                    builder.AppendLine("    No body");
-                }
-                else
-                {
-                    var body = entry.Body;
-
-                    builder.AppendLine(body.DiscTypeIdentifier, "    Disc type identifer");
-                    builder.AppendLine(body.DiscSizeClassVersion, "    Disc size class version");
-                    builder.AppendLine(body.FormatDependentContents, "    Format-dependent contents");
-                }
+                var body = entry.Body;
+                builder.AppendLine(body.DiscTypeIdentifier, "    Disc type identifer");
+                builder.AppendLine(body.DiscSizeClassVersion, "    Disc size class version");
+                builder.AppendLine(body.FormatDependentContents, "    Format-dependent contents");
 
                 if (entry.Trailer == null)
                 {
diff --git a/SabreTools.Serialization/Wrappers/PIC.cs b/SabreTools.Serialization/Wrappers/PIC.cs
index 7b6fcb2c..e53695f0 100644
--- a/SabreTools.Serialization/Wrappers/PIC.cs
+++ b/SabreTools.Serialization/Wrappers/PIC.cs
@@ -15,7 +15,7 @@ namespace SabreTools.Serialization.Wrappers
         #region Extension Properties
 
         /// <inheritdoc cref="DiscInformation.Units"/>
-        public DiscInformationUnit[] Units => Model.Units ?? [];
+        public DiscInformationUnit[] Units => Model.Units;
 
         #endregion