diff --git a/fastdeploy/pybind/fd_tensor.cc b/fastdeploy/pybind/fd_tensor.cc
index 52e7fca57..28c5e2b53 100644
--- a/fastdeploy/pybind/fd_tensor.cc
+++ b/fastdeploy/pybind/fd_tensor.cc
@@ -69,7 +69,7 @@ DLDataType FDToDlpackType(FDDataType fd_dtype) {
 
     default:
       FDASSERT(false,
-              "Convert to DlPack, FDType \"%s\" is not supported.", Str(fd_dtype));
+              "Convert to DlPack, FDType \"%s\" is not supported.", Str(fd_dtype).c_str());
   }
 
   dl_dtype.code = dl_code;