diff --git a/src/login/logind-brightness.c b/src/login/logind-brightness.c
index 5c0c55fc36..450ec32044 100644
--- a/src/login/logind-brightness.c
+++ b/src/login/logind-brightness.c
@@ -175,9 +175,8 @@ static int set_add_message(Set **set, sd_bus_message *message) {
                 return r;
 
         r = set_ensure_put(set, &bus_message_hash_ops, message);
-        if (r < 0)
+        if (r <= 0)
                 return r;
-
         sd_bus_message_ref(message);
 
         return 1;