diff --git a/src/transformers/models/maskformer/modeling_maskformer.py b/src/transformers/models/maskformer/modeling_maskformer.py
index eef31ba2799a45..f2b171b32dc9e4 100644
--- a/src/transformers/models/maskformer/modeling_maskformer.py
+++ b/src/transformers/models/maskformer/modeling_maskformer.py
@@ -1439,7 +1439,7 @@ def __init__(self, config: MaskFormerConfig):
                 The configuration used to instantiate this model.
         """
         super().__init__()
-        if hasattr(config, "backbone_config") and config.backbone_config.model_type == "swin":
+        if getattr(config, "backbone_config") is not None and config.backbone_config.model_type == "swin":
             # for backwards compatibility
             backbone_config = config.backbone_config
             backbone_config = MaskFormerSwinConfig.from_dict(backbone_config.to_dict())