diff --git a/tools/lint/commands.c b/tools/lint/commands.c
index 0ff821b..3c7cf01 100644
--- a/tools/lint/commands.c
+++ b/tools/lint/commands.c
@@ -647,7 +647,7 @@
         } else {
 #endif
 
-            lyd_parse_data(ctx, in, 0, opts, 0, &data);
+            lyd_parse_data(ctx, in, 0, opts, LYD_VALIDATE_PRESENT, &data);
 #if 0
         }
     }
@@ -734,12 +734,10 @@
         case 'f':
             if (!strcmp(optarg, "xml")) {
                 outformat = LYD_XML;
-#if 0
             } else if (!strcmp(optarg, "json")) {
                 outformat = LYD_JSON;
             } else if (!strcmp(optarg, "lyb")) {
                 outformat = LYD_LYB;
-#endif
             } else {
                 fprintf(stderr, "Unknown output format \"%s\".\n", optarg);
                 goto cleanup;
diff --git a/tools/lint/main_ni.c b/tools/lint/main_ni.c
index 2b49ee6..f3e955c 100644
--- a/tools/lint/main_ni.c
+++ b/tools/lint/main_ni.c
@@ -229,11 +229,9 @@
         } else if (!strcmp(ptr, "xml")) {
             informat_s = 0;
             informat_d = LYD_XML;
-#if 0
         } else if (!strcmp(ptr, "json")) {
             informat_s = 0;
             informat_d = LYD_JSON;
-#endif
         } else {
             fprintf(stderr, "yanglint error: input file in an unknown format \"%s\".\n", ptr);
             return 0;
@@ -391,11 +389,9 @@
             } else if (!strcasecmp(optarg, "xml")) {
                 outformat_s = 0;
                 outformat_d = LYD_XML;
-#if 0
             } else if (!strcasecmp(optarg, "json")) {
                 outformat_s = 0;
                 outformat_d = LYD_JSON;
-#endif
             } else {
                 fprintf(stderr, "yanglint error: unknown output format %s\n", optarg);
                 help(1);
@@ -971,7 +967,7 @@
                     fprintf(stderr, "yanglint error: input data file \"%s\".\n", data_item->filename);
                     goto cleanup;
                 }
-                if (lyd_parse_data(ctx, in, 0, options_parser, 0, &data_item->tree)) {
+                if (lyd_parse_data(ctx, in, 0, options_parser, LYD_VALIDATE_PRESENT, &data_item->tree)) {
                     fprintf(stderr, "yanglint error: Failed to parse input data file \"%s\".\n", data_item->filename);
                     ly_in_free(in, 0);
                     goto cleanup;
@@ -1067,6 +1063,9 @@
                     }
                 }
 #endif
+                if (!out) {
+                    ly_out_new_file(stdout, &out);
+                }
                 lyd_print_all(out, data_item->tree, outformat_d, LYD_PRINT_FORMAT /* TODO defaults | options_dflt */);
 #if 0
                 if (envelope_s) {