diff --git a/ClosedXML/Excel/PivotTables/XLPivotField.cs b/ClosedXML/Excel/PivotTables/XLPivotField.cs
index dbdfac9..1f8ac67 100644
--- a/ClosedXML/Excel/PivotTables/XLPivotField.cs
+++ b/ClosedXML/Excel/PivotTables/XLPivotField.cs
@@ -5,7 +5,7 @@
 namespace ClosedXML.Excel
 {
     [DebuggerDisplay("{SourceName}")]
-    public class XLPivotField : IXLPivotField
+    internal class XLPivotField : IXLPivotField
     {
         public XLPivotField(string sourceName)
         {