diff --git a/C4/Letters.pm b/C4/Letters.pm
index c2f540c072..26d866d7f0 100644
--- a/C4/Letters.pm
+++ b/C4/Letters.pm
@@ -1804,6 +1804,7 @@ sub _process_tt {
         {
             EVAL_PERL    => 0,
             ABSOLUTE     => 0,
+            RELATIVE     => 0,
             PLUGIN_BASE  => 'Koha::Template::Plugin',
             COMPILE_EXT  => $use_template_cache ? '.ttc'                                    : '',
             COMPILE_DIR  => $use_template_cache ? C4::Context->config('template_cache_dir') : '',