diff --git a/ppcls/arch/__init__.py b/ppcls/arch/__init__.py
index ecc1af793a4c6ec0eeba3d0a567da0b90bb1c485..3a0738e1ec8e31bfd9efe05c65e9565b26bf5200 100644
--- a/ppcls/arch/__init__.py
+++ b/ppcls/arch/__init__.py
@@ -64,6 +64,7 @@ def apply_to_static(config, model):
         specs = None
         if 'image_shape' in config['Global']:
             specs = [InputSpec([None] + config['Global']['image_shape'])]
+            specs[0].stop_gradient = True
         model = to_static(model, input_spec=specs)
         logger.info("Successfully to apply @to_static with specs: {}".format(
             specs))