diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/catalogue/detail.tt b/koha-tmpl/intranet-tmpl/prog/en/modules/catalogue/detail.tt
index be5932bea6..c3d9df303d 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/catalogue/detail.tt
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/catalogue/detail.tt
@@ -467,12 +467,12 @@
                                     <span class="enum">[% item.enumchron %]</span>
                                     [% IF ( item.serialseq && item.enumchron!=item.serialseq ) %]
                                         <span class="sep"> -- </span>
-                                        <span class="serialseq">[% item.serialseq %]</span>
+                                        <span class="serialseq">[% item.serialseq | html %]</span>
                                     [% END %]
                                 [% ELSIF item.enumchron %]
-                                    <span class="enum">[% item.enumchron %]</span>
+                                    <span class="enum">[% item.enumchron | html %]</span>
                                 [% ELSIF item.serialseq %]
-                                    <span class="serialseq">[% item.serialseq %]</span>
+                                    <span class="serialseq">[% item.serialseq | html %]</span>
                                 [% END %]
                                 [% IF ( item.publisheddate ) %]
                                     <span class="pubdate">([% item.publisheddate | $KohaDates %])</span>
diff --git a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-detail.tt b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-detail.tt
index a937946090..97ea7a0b42 100644
--- a/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-detail.tt
+++ b/koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-detail.tt
@@ -1307,12 +1307,12 @@
                                 <span class="enum">[% ITEM_RESULT.enumchron %]</span>
                                 [% IF ( ITEM_RESULT.serialseq && ITEM_RESULT.enumchron!=ITEM_RESULT.serialseq ) %]
                                     <span class="sep"> -- </span>
-                                    <span class="serialseq">[% ITEM_RESULT.serialseq %]</span>
+                                    <span class="serialseq">[% ITEM_RESULT.serialseq | html %]</span>
                                 [% END %]
                             [% ELSIF ITEM_RESULT.enumchron %]
-                                <span class="enum">[% ITEM_RESULT.enumchron %]</span>
+                                <span class="enum">[% ITEM_RESULT.enumchron | html %]</span>
                             [% ELSIF ITEM_RESULT.serialseq %]
-                                    <span class="serialseq">[% ITEM_RESULT.serialseq %]</span>
+                                    <span class="serialseq">[% ITEM_RESULT.serialseq | html %]</span>
                             [% END %]
                             [% IF ( ITEM_RESULT.publisheddate ) %]
                                 <span class="pubdate">([% ITEM_RESULT.publisheddate | $KohaDates %])</span>