diff --git a/src/PdfSharp/Pdf/PdfPages.cs b/src/PdfSharp/Pdf/PdfPages.cs
index de2ee441..b9ee3d5f 100644
--- a/src/PdfSharp/Pdf/PdfPages.cs
+++ b/src/PdfSharp/Pdf/PdfPages.cs
@@ -360,7 +360,7 @@ public void InsertRange(int index, PdfDocument document, int startIndex, int pag
                     if (annotations.Count > 0)
                     {
                         //Owner._irefTable.Add(annotations);
-                        page.Elements.Add(PdfPage.Keys.Annots, annotations);
+                        page.Elements[PdfPage.Keys.Annots] = annotations;
                     }
                 }