diff --git a/PicoGK_Csv.cs b/PicoGK_Csv.cs
index ad7e6d3..c7c4d65 100644
--- a/PicoGK_Csv.cs
+++ b/PicoGK_Csv.cs
@@ -57,7 +57,7 @@ public class CsvTable : IDataTable
     {
         public CsvTable(IEnumerable<string>? astrColumnIDs = null)
         {
-            m_oColumnIDs = new(astrColumnIDs ?? []);
+            m_oColumnIDs = new(astrColumnIDs ?? new List<string>());
         }
         public CsvTable(  string strFilePath,
                           string strDelimiters = ",")