diff --git a/installer/data/mysql/atomicupdate/bug_32478-fix_NULL_values_in_syspref_ItemsDeniedRenewal.pl b/installer/data/mysql/atomicupdate/bug_32478-fix_NULL_values_in_syspref_ItemsDeniedRenewal.pl
new file mode 100755
index 0000000000..d7c67b6bc8
--- /dev/null
+++ b/installer/data/mysql/atomicupdate/bug_32478-fix_NULL_values_in_syspref_ItemsDeniedRenewal.pl
@@ -0,0 +1,17 @@
+use Modern::Perl;
+use C4::Context;
+
+return {
+    bug_number => "32478",
+    description => "Remove usage of Koha::Config::SysPref->find since bypasses cache",
+    up => sub {
+        my ($args) = @_;
+        my ($dbh, $out) = @$args{qw(dbh out)};
+
+        $dbh->do(q{UPDATE `systempreferences` SET `value` = REPLACE(`value`, 'NULL', 'null') WHERE `variable` = 'ItemsDeniedRenewal'});
+        say $out "Replace 'NULL' with 'null' in ItemsDeniedRenewal system preference";
+
+        C4::Context->clear_syspref_cache();
+        say $out "Clear system preference cache";
+    },
+};
diff --git a/koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/circulation.pref b/koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/circulation.pref
index 6c3ee2c27b..c5308a8506 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/circulation.pref
+++ b/koha-tmpl/intranet-tmpl/prog/en/modules/admin/preferences/circulation.pref
@@ -540,9 +540,9 @@ Circulation:
             - "<br />Can name any field in the items table followed by a colon then a space then"
             - "a bracketed list of values separated by commas."
             - "For example:"
-            - "<br />ccode: [NEWFIC,NULL,DVD]"
+            - "<br />ccode: [NEWFIC,null,DVD]"
             - "<br />itype: [NEWBK,\"\"]"
-            - "<br /> <strong>NOTE:</strong> The word 'NULL' can be used to block renewal on undefined fields, while an empty string \"\" will block on an empty (but defined) field."
+            - "<br /> <strong>NOTE:</strong> The word 'null' can be used to block renewal on undefined fields, while an empty string \"\" will block on an empty (but defined) field."
         -
             - pref: UpdateNotForLoanStatusOnCheckout
               type: textarea