diff --git a/src/UglyToad.PdfPig.Tests/PublicApiScannerTests.cs b/src/UglyToad.PdfPig.Tests/PublicApiScannerTests.cs
index 586bc4bc..a853ca40 100644
--- a/src/UglyToad.PdfPig.Tests/PublicApiScannerTests.cs
+++ b/src/UglyToad.PdfPig.Tests/PublicApiScannerTests.cs
@@ -197,6 +197,7 @@
                 "UglyToad.PdfPig.Util.IWordExtractor",
                 "UglyToad.PdfPig.Util.DefaultWordExtractor",
                 "UglyToad.PdfPig.Util.DateFormatHelper",
+                "UglyToad.PdfPig.Util.WhitespaceSizeStatistics",
                 "UglyToad.PdfPig.Writer.PdfAStandard",
                 "UglyToad.PdfPig.Writer.PdfDocumentBuilder",
                 "UglyToad.PdfPig.Writer.PdfMerger",