diff --git a/src/builtin-adapter/BUILD b/src/builtin-adapter/BUILD
index b16c391d..38d986e1 100644
--- a/src/builtin-adapter/BUILD
+++ b/src/builtin-adapter/BUILD
@@ -145,6 +145,7 @@ cc_binary(
         ":models_to_json_lib",
         ":visualize_config",
         "@com_google_absl//absl/log",
+        "@com_google_absl//absl/status",
         "@com_google_absl//absl/status:statusor",
         "@org_tensorflow//tensorflow/compiler/mlir:init_mlir",
         "@org_tensorflow//tensorflow/compiler/mlir/lite/tools:command_line_flags",
diff --git a/src/builtin-adapter/models_to_json_main.cc b/src/builtin-adapter/models_to_json_main.cc
index 4290486b..1ba9b034 100644
--- a/src/builtin-adapter/models_to_json_main.cc
+++ b/src/builtin-adapter/models_to_json_main.cc
@@ -17,6 +17,7 @@
 #include <vector>
 
 #include "absl/log/log.h"
+#include "absl/status/status.h"
 #include "absl/status/statusor.h"
 #include "tensorflow/compiler/mlir/init_mlir.h"
 #include "models_to_json_lib.h"
@@ -47,9 +48,9 @@ int main(int argc, char* argv[]) {
   std::vector<mlir::Flag> flag_list = {
       mlir::Flag::CreateFlag(kInputFileFlag, &input_file,
                              "Input filename or directory",
-                             mlir::Flag::kRequired),
+                             mlir::Flag::kOptional),
       mlir::Flag::CreateFlag(kOutputFileFlag, &output_file, "Output filename",
-                             mlir::Flag::kRequired),
+                             mlir::Flag::kOptional),
       mlir::Flag::CreateFlag(
           kConstElementCountLimitFlag, &const_element_count_limit,
           "The maximum number of constant elements. If the number exceeds this "
@@ -69,6 +70,11 @@ int main(int argc, char* argv[]) {
     return 1;
   }
 
+  if (output_file.empty()) {
+    LOG(ERROR) << "Output filename cannot be empty.";
+    return 1;
+  }
+
   if (output_file.substr(output_file.size() - 4, 4) != "json") {
     LOG(WARNING) << "Please specify output format to be JSON.";
   }