diff --git a/nvflare/app_opt/pt/numpy_params_converter.py b/nvflare/app_opt/pt/numpy_params_converter.py
index 503da8e284..10bdda7f9c 100644
--- a/nvflare/app_opt/pt/numpy_params_converter.py
+++ b/nvflare/app_opt/pt/numpy_params_converter.py
@@ -48,7 +48,15 @@ def convert(self, params: Dict, fl_ctx) -> Dict:
         exclude_vars = {}
         for k, v in params.items():
             if isinstance(v, torch.Tensor):
-                return_tensors[k] = v.cpu().numpy()
+                # Check type of tensor and convert to numpy
+                data_type = str(v.dtype).split(".")[1]
+                # Numpy does not support bfloat16, give error
+                if data_type == "bfloat16":
+                    raise ValueError(
+                        f"Unsupported data type for numpy transmission: {data_type}, please use pytorch exchange format or convert params to a supported data type (fp32, fp16, etc.)"
+                    )
+                else:
+                    return_tensors[k] = v.cpu().numpy()
                 tensor_shapes[k] = v.shape
             else:
                 exclude_vars[k] = v