diff --git a/ena_upload/templates/ENA_template_experiments.xml b/ena_upload/templates/ENA_template_experiments.xml
index 9f87bab..71254e6 100755
--- a/ena_upload/templates/ENA_template_experiments.xml
+++ b/ena_upload/templates/ENA_template_experiments.xml
@@ -49,7 +49,7 @@ def mandatorytest(row, column, index):
                     </py:if>
                     <py:if test="mandatorytest(row, 'library_layout', index)">
                     <LIBRARY_LAYOUT py:choose="">
-                        <PAIRED py:when="row.library_layout.lower().strip() == 'paired'" NOMINAL_LENGTH="${row.insert_size}" />
+                        <PAIRED py:when="row.library_layout.lower().strip() == 'paired'" NOMINAL_LENGTH="${int(row.insert_size)}" />
                         <SINGLE py:when="row.library_layout.lower().strip() == 'single'" />
                     </LIBRARY_LAYOUT>
                     </py:if>