diff --git a/Koha/Illrequest.pm b/Koha/Illrequest.pm
index 7ea301fde3..6d26418cd9 100644
--- a/Koha/Illrequest.pm
+++ b/Koha/Illrequest.pm
@@ -569,7 +569,8 @@ sub _status_graph_union {
             if ( grep { $prev_action eq $_ } @core_status_ids ) {
                 my @next_actions =
                      @{$status_graph->{$prev_action}->{next_actions}};
-                push @next_actions, $backend_status_key;
+                push @next_actions, $backend_status_key
+                    if (!grep(/^$backend_status_key$/, @next_actions));
                 $status_graph->{$prev_action}->{next_actions}
                     = \@next_actions;
             }
@@ -579,7 +580,8 @@ sub _status_graph_union {
             if ( grep { $next_action eq $_ } @core_status_ids ) {
                 my @prev_actions =
                      @{$status_graph->{$next_action}->{prev_actions}};
-                push @prev_actions, $backend_status_key;
+                push @prev_actions, $backend_status_key
+                    if (!grep(/^$backend_status_key$/, @prev_actions));
                 $status_graph->{$next_action}->{prev_actions}
                     = \@prev_actions;
             }