diff --git a/sherpa-onnx/csrc/offline-ctc-model.cc b/sherpa-onnx/csrc/offline-ctc-model.cc
index 5a6fb1858..0bfa56add 100644
--- a/sherpa-onnx/csrc/offline-ctc-model.cc
+++ b/sherpa-onnx/csrc/offline-ctc-model.cc
@@ -34,6 +34,8 @@ static ModelType GetModelType(char *model_data, size_t model_data_length,
                               bool debug) {
   Ort::Env env(ORT_LOGGING_LEVEL_WARNING);
   Ort::SessionOptions sess_opts;
+  sess_opts.SetIntraOpNumThreads(1);
+  sess_opts.SetInterOpNumThreads(1);
 
   auto sess = std::make_unique<Ort::Session>(env, model_data, model_data_length,
                                              sess_opts);
diff --git a/sherpa-onnx/csrc/offline-recognizer-impl.cc b/sherpa-onnx/csrc/offline-recognizer-impl.cc
index 488e7e7f3..c89b868e3 100644
--- a/sherpa-onnx/csrc/offline-recognizer-impl.cc
+++ b/sherpa-onnx/csrc/offline-recognizer-impl.cc
@@ -40,6 +40,9 @@ std::unique_ptr<OfflineRecognizerImpl> OfflineRecognizerImpl::Create(
   Ort::Env env(ORT_LOGGING_LEVEL_ERROR);
 
   Ort::SessionOptions sess_opts;
+  sess_opts.SetIntraOpNumThreads(1);
+  sess_opts.SetInterOpNumThreads(1);
+
   std::string model_filename;
   if (!config.model_config.transducer.encoder_filename.empty()) {
     model_filename = config.model_config.transducer.encoder_filename;
@@ -167,6 +170,9 @@ std::unique_ptr<OfflineRecognizerImpl> OfflineRecognizerImpl::Create(
   Ort::Env env(ORT_LOGGING_LEVEL_ERROR);
 
   Ort::SessionOptions sess_opts;
+  sess_opts.SetIntraOpNumThreads(1);
+  sess_opts.SetInterOpNumThreads(1);
+
   std::string model_filename;
   if (!config.model_config.transducer.encoder_filename.empty()) {
     model_filename = config.model_config.transducer.encoder_filename;
diff --git a/sherpa-onnx/csrc/online-transducer-model.cc b/sherpa-onnx/csrc/online-transducer-model.cc
index 2bc9acc53..6a1fe5d55 100644
--- a/sherpa-onnx/csrc/online-transducer-model.cc
+++ b/sherpa-onnx/csrc/online-transducer-model.cc
@@ -39,6 +39,8 @@ static ModelType GetModelType(char *model_data, size_t model_data_length,
                               bool debug) {
   Ort::Env env(ORT_LOGGING_LEVEL_WARNING);
   Ort::SessionOptions sess_opts;
+  sess_opts.SetIntraOpNumThreads(1);
+  sess_opts.SetInterOpNumThreads(1);
 
   auto sess = std::make_unique<Ort::Session>(env, model_data, model_data_length,
                                              sess_opts);
diff --git a/sherpa-onnx/csrc/speaker-embedding-extractor-impl.cc b/sherpa-onnx/csrc/speaker-embedding-extractor-impl.cc
index 52466edc5..53ff99408 100644
--- a/sherpa-onnx/csrc/speaker-embedding-extractor-impl.cc
+++ b/sherpa-onnx/csrc/speaker-embedding-extractor-impl.cc
@@ -25,6 +25,8 @@ static ModelType GetModelType(char *model_data, size_t model_data_length,
                               bool debug) {
   Ort::Env env(ORT_LOGGING_LEVEL_WARNING);
   Ort::SessionOptions sess_opts;
+  sess_opts.SetIntraOpNumThreads(1);
+  sess_opts.SetInterOpNumThreads(1);
 
   auto sess = std::make_unique<Ort::Session>(env, model_data, model_data_length,
                                              sess_opts);