diff --git a/src/deepforest/model.py b/src/deepforest/model.py
index e667a03e1..9a21dcf7d 100644
--- a/src/deepforest/model.py
+++ b/src/deepforest/model.py
@@ -265,11 +265,15 @@ def get_transform(self, augmentations):
 
         resize_dims = self.config["cropmodel"].get("resize", [224, 224])
         interp_name = self.config["cropmodel"].get("resize_interpolation", "bilinear")
-        interp = (
-            transforms.InterpolationMode.NEAREST
-            if interp_name == "nearest"
-            else transforms.InterpolationMode.BILINEAR
-        )
+        if interp_name == "nearest":
+            interp = transforms.InterpolationMode.NEAREST
+        elif interp_name == "bilinear":
+            interp = transforms.InterpolationMode.BILINEAR
+        else:
+            raise ValueError(
+                f"Invalid resize_interpolation '{interp_name}'. "
+                "Supported values are ['nearest', 'bilinear']."
+            )
         data_transforms.append(transforms.Resize(resize_dims, interpolation=interp))
 
         # Apply augmentations if specified
@@ -281,7 +285,9 @@ def get_transform(self, augmentations):
 
         return transforms.Compose(data_transforms)
 
-    def expand_bbox_to_square(self, bbox, image_width, image_height):
+    def expand_bbox_to_square(
+        self, bbox: list[float], image_width: int, image_height: int
+    ) -> list[float]:
         """Expand a bounding box to a square by extending the shorter side.
 
         Parameters: