diff --git a/torchgeo/trainers/base.py b/torchgeo/trainers/base.py
index d9677e390a6..43573731833 100644
--- a/torchgeo/trainers/base.py
+++ b/torchgeo/trainers/base.py
@@ -35,7 +35,9 @@ def __init__(self, ignore: Optional[Union[Sequence[str], str]] = None) -> None:
             ignore: Arguments to skip when saving hyperparameters.
         """
         super().__init__()
-        if isinstance(ignore, str):
+        if ignore is None:
+            ignore = ["ignore"]
+        elif isinstance(ignore, str):
             ignore = [ignore, "ignore"]
         else:
             ignore = list(ignore) + ["ignore"]