diff --git a/graph_weather/models/gencast/README.md b/graph_weather/models/gencast/README.md
new file mode 100644
index 00000000..d5e04e62
--- /dev/null
+++ b/graph_weather/models/gencast/README.md
@@ -0,0 +1,2 @@
+# GenCast
+
diff --git a/graph_weather/models/gencast/graph/graph_builder.py b/graph_weather/models/gencast/graph/graph_builder.py
index 0a0566e5..23abccb0 100644
--- a/graph_weather/models/gencast/graph/graph_builder.py
+++ b/graph_weather/models/gencast/graph/graph_builder.py
@@ -71,7 +71,7 @@ def __init__(
         grid_lat: np.ndarray,
         splits: int = 5,
         num_hops: int = 0,
-        device: str = "cpu",
+        device: torch.device = torch.device("cpu"),
     ):
         """Initialize the GraphBuilder object.