diff --git a/fastNLP/core/field.py b/fastNLP/core/field.py
index b9a8196c..faa306f3 100644
--- a/fastNLP/core/field.py
+++ b/fastNLP/core/field.py
@@ -62,6 +62,7 @@ class FieldArray:
         if value:
             self._cell_ndim = None
             self.dtype = None
+        self._ignore_type = value
 
     @property
     def is_input(self):