diff --git a/dataverse-webapp/src/main/java/edu/harvard/iq/dataverse/api/dto/UningestableItemDTO.java b/dataverse-webapp/src/main/java/edu/harvard/iq/dataverse/api/dto/UningestableItemDTO.java
index c02a7d5841a..383f5db9a41 100644
--- a/dataverse-webapp/src/main/java/edu/harvard/iq/dataverse/api/dto/UningestableItemDTO.java
+++ b/dataverse-webapp/src/main/java/edu/harvard/iq/dataverse/api/dto/UningestableItemDTO.java
@@ -51,7 +51,7 @@ public static UningestableItemDTO fromDatafile(DataFile file) {
 
     // -------------------- PRIVATE --------------------
 
-    public static String extractAndFormatExtension(DataFile file) {
+    private static String extractAndFormatExtension(DataFile file) {
         String extension = FileUtil.generateOriginalExtension(file.isTabularData()
                 ? file.getDataTable().getOriginalFileFormat()
                 : file.getContentType());