diff --git a/lavis/models/base_model.py b/lavis/models/base_model.py
index 44d66f3fc..152585400 100644
--- a/lavis/models/base_model.py
+++ b/lavis/models/base_model.py
@@ -98,7 +98,7 @@ def load_checkpoint_from_config(self, cfg, **kwargs):
             if load_pretrained:
                 # load pre-trained weights
                 pretrain_path = cfg.get("pretrained", None)
-                assert "Found load_finetuned is False, but pretrain_path is None."
+                assert pretrain_path is not None, "Found load_finetuned is False, but pretrain_path is None."
                 self.load_from_pretrained(url_or_filename=pretrain_path, **kwargs)
 
     def before_training(self, **kwargs):