diff --git a/CHANGES.rst b/CHANGES.rst
index 65377711e8..c59420d744 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -4,6 +4,7 @@ Changelog
 2.7.0 (unreleased)
 ------------------
 
+- #2960 Set multipart enctype on the sample header form so file uploads persist
 - #2957 Harmonize form input widths via tunable CSS variables
 - #2956 Restrict client discount fields to lab staff
 - #2958 Add labels with colors, filtering, and bulk-manage modal for samples
diff --git a/src/senaite/core/browser/viewlets/templates/sampleheader.pt b/src/senaite/core/browser/viewlets/templates/sampleheader.pt
index db44dcdba7..3d25d70b55 100644
--- a/src/senaite/core/browser/viewlets/templates/sampleheader.pt
+++ b/src/senaite/core/browser/viewlets/templates/sampleheader.pt
@@ -29,7 +29,8 @@
       <form id="senaite-sampleheader-form"
             name="sampleheader_form"
             class="senaite-form"
-            method="post" novalidate>
+            method="post" novalidate
+            enctype="multipart/form-data">
 
         <!-- Hidden fields -->
         <input type="hidden" name="sampleheader_form_submitted" value="1" />