diff --git a/selfdrive/modeld/runners/snpemodel.cc b/selfdrive/modeld/runners/snpemodel.cc
index bab7432207..4f3d8f58a3 100644
--- a/selfdrive/modeld/runners/snpemodel.cc
+++ b/selfdrive/modeld/runners/snpemodel.cc
@@ -9,8 +9,9 @@ void PrintErrorStringAndExit() {
   std::exit(EXIT_FAILURE);
 }
 
-SNPEModel::SNPEModel(const char *path, float *loutput, size_t output_size, int runtime) {
+SNPEModel::SNPEModel(const char *path, float *loutput, size_t loutput_size, int runtime) {
   output = loutput;
+  output_size = loutput_size;
 #ifdef QCOM
   if (runtime==USE_GPU_RUNTIME) {
     Runtime = zdl::DlSystem::Runtime_t::GPU;
@@ -102,6 +103,7 @@ SNPEModel::SNPEModel(const char *path, float *loutput, size_t output_size, int r
 
 void SNPEModel::addRecurrent(float *state, int state_size) {
   recurrent = state;
+  recurrent_size = state_size;
   recurrentBuffer = this->addExtra(state, state_size, 3);
 }
 
@@ -134,21 +136,37 @@ std::unique_ptr<zdl::DlSystem::IUserBuffer> SNPEModel::addExtra(float *state, in
 void SNPEModel::execute(float *net_input_buf, int buf_size) {
 #ifdef USE_THNEED
   if (Runtime == zdl::DlSystem::Runtime_t::GPU) {
+    float *inputs[4] = {recurrent, trafficConvention, desire, net_input_buf};
     if (thneed == NULL) {
       assert(inputBuffer->setBufferAddress(net_input_buf));
       if (!snpe->execute(inputMap, outputMap)) {
         PrintErrorStringAndExit();
       }
+      memset(recurrent, 0, recurrent_size*sizeof(float));
       thneed = new Thneed();
-      //thneed->record = 3;
       if (!snpe->execute(inputMap, outputMap)) {
         PrintErrorStringAndExit();
       }
       thneed->stop();
-      //thneed->record = 2;
       printf("thneed cached\n");
+
+      // doing self test
+      float *outputs_golden = (float *)malloc(output_size*sizeof(float));
+      memcpy(outputs_golden, output, output_size*sizeof(float));
+      memset(output, 0, output_size*sizeof(float));
+      memset(recurrent, 0, recurrent_size*sizeof(float));
+      thneed->execute(inputs, output);
+
+      if (memcmp(output, outputs_golden, output_size*sizeof(float)) == 0) {
+        printf("thneed selftest passed\n");
+      } else {
+        for (int i = 0; i < output_size; i++) {
+          printf("mismatch %3d: %f %f\n", i, output[i], outputs_golden[i]);
+        }
+        assert(false);
+      }
+      free(outputs_golden);
     } else {
-      float *inputs[4] = {recurrent, trafficConvention, desire, net_input_buf};
       thneed->execute(inputs, output);
     }
   } else {
diff --git a/selfdrive/modeld/runners/snpemodel.h b/selfdrive/modeld/runners/snpemodel.h
index 496ad51db2..11aa14ccb5 100644
--- a/selfdrive/modeld/runners/snpemodel.h
+++ b/selfdrive/modeld/runners/snpemodel.h
@@ -23,7 +23,7 @@
 
 class SNPEModel : public RunModel {
 public:
-  SNPEModel(const char *path, float *loutput, size_t output_size, int runtime);
+  SNPEModel(const char *path, float *loutput, size_t loutput_size, int runtime);
   ~SNPEModel() {
     if (model_data) free(model_data);
   }
@@ -51,10 +51,12 @@ private:
   zdl::DlSystem::UserBufferMap outputMap;
   std::unique_ptr<zdl::DlSystem::IUserBuffer> outputBuffer;
   float *output;
+  size_t output_size;
 
   // recurrent and desire
   std::unique_ptr<zdl::DlSystem::IUserBuffer> addExtra(float *state, int state_size, int idx);
   float *recurrent;
+  size_t recurrent_size;
   std::unique_ptr<zdl::DlSystem::IUserBuffer> recurrentBuffer;
   float *trafficConvention;
   std::unique_ptr<zdl::DlSystem::IUserBuffer> trafficConventionBuffer;