diff --git a/C4/AuthoritiesMarc.pm b/C4/AuthoritiesMarc.pm
index ab62a5d962..4cbed9e95d 100644
--- a/C4/AuthoritiesMarc.pm
+++ b/C4/AuthoritiesMarc.pm
@@ -1750,7 +1750,9 @@ sub merge {
                     if ( defined $controlled_ind->{sub2} ) {
 
                         # Add or replace
-                        $field_to->update( 2 => $controlled_ind->{sub2} );
+                        if ( $controlled_ind->{sub2} ne q{} ) {
+                            $field_to->update( 2 => $controlled_ind->{sub2} );
+                        }
                     } else {
 
                         # Key alerts us here to remove $2