diff --git a/Koha/Item.pm b/Koha/Item.pm
index e0e1505d3a..65b55558b1 100644
--- a/Koha/Item.pm
+++ b/Koha/Item.pm
@@ -148,9 +148,7 @@ sub store {
             $self->permanent_location( $self->location );
         }
 
-        if ( $self->timestamp ) {
-            $self->timestamp(dt_from_string); # Maybe move this to Koha::Object->store?
-        }
+        $self->timestamp(undef) if $self->timestamp; # Maybe move this to Koha::Object->store?
 
         C4::Biblio::ModZebra( $self->biblionumber, "specialUpdate", "biblioserver" );
 
diff --git a/Koha/Object.pm b/Koha/Object.pm
index 11074498ba..fcb1e802ff 100644
--- a/Koha/Object.pm
+++ b/Koha/Object.pm
@@ -151,6 +151,12 @@ sub store {
                     $self->_result()->set_column($col => $columns_info->{$col}->{default_value});
                 }
             }
+            elsif ( not defined $self->$col
+                  && $columns_info->{$col}->{datetime_undef_if_invalid} )
+              {
+                  # timestamp
+                  $self->$col( $columns_info->{$col}->{default_value} );
+              }
         }
     }