diff --git a/apps/emqx/src/emqx_schema.erl b/apps/emqx/src/emqx_schema.erl
index 29c201ad6..334d2cf27 100644
--- a/apps/emqx/src/emqx_schema.erl
+++ b/apps/emqx/src/emqx_schema.erl
@@ -965,7 +965,7 @@ fields("tcp_opts") ->
     [
         {"active_n",
             sc(
-                integer(),
+                non_neg_integer(),
                 #{
                     default => 100,
                     desc => ?DESC(fields_tcp_opts_active_n)