diff --git a/README.md b/README.md
index 56538da..ed40ab5 100644
--- a/README.md
+++ b/README.md
@@ -1678,7 +1678,6 @@ namespace nietras.SeparatedValues
     }
     public sealed class SepReaderHeader
     {
-        public SepReaderHeader(string row, System.Collections.Generic.Dictionary<string, int> colNameToIndex) { }
         public System.Collections.Generic.IReadOnlyList<string> ColNames { get; }
         public bool IsEmpty { get; }
         public static nietras.SeparatedValues.SepReaderHeader Empty { get; }
diff --git a/src/Sep/SepReaderHeader.cs b/src/Sep/SepReaderHeader.cs
index e7ed1b5..0d77cf4 100644
--- a/src/Sep/SepReaderHeader.cs
+++ b/src/Sep/SepReaderHeader.cs
@@ -10,14 +10,14 @@ public sealed class SepReaderHeader
     readonly Dictionary<string, int> _colNameToIndex;
     readonly string[] _colNames;
 
-    public SepReaderHeader(string row, Dictionary<string, int> colNameToIndex)
+    internal SepReaderHeader(string row, Dictionary<string, int> colNameToIndex)
     {
         _row = row;
         _colNameToIndex = colNameToIndex;
         _colNames = _colNameToIndex.Keys.ToArray();
     }
 
-    public static SepReaderHeader Empty { get; } = new(string.Empty, new Dictionary<string, int>());
+    public static SepReaderHeader Empty { get; } = new(string.Empty, []);
 
     internal static SepReaderHeader Parse(Sep sep, string line) =>
         Parse(sep, line, SepDefaults.ColNameComparer);