diff --git a/torchvision/prototype/models/depth/stereo/crestereo.py b/torchvision/prototype/models/depth/stereo/crestereo.py
index 49643852285..29c0be93618 100644
--- a/torchvision/prototype/models/depth/stereo/crestereo.py
+++ b/torchvision/prototype/models/depth/stereo/crestereo.py
@@ -763,7 +763,7 @@ def _get_window_type(self, iteration: int) -> str:
         return "1d" if iteration % 2 == 0 else "2d"
 
     def forward(
-        self, left_image: Tensor, right_image: Tensor, flow_init: Optional[Tensor], num_iters: int = 10
+        self, left_image: Tensor, right_image: Tensor, flow_init: Optional[Tensor] = None, num_iters: int = 10
     ) -> List[Tensor]:
         features = torch.cat([left_image, right_image], dim=0)
         features = self.feature_encoder(features)
@@ -781,10 +781,10 @@ def forward(
         ctx_pyramid = self.downsampling_pyramid(ctx)
 
         # we store in reversed order because we process the pyramid from top to bottom
-        l_pyramid: Dict[str, Tensor] = {res: l_pyramid[idx] for idx, res in enumerate(self.resolutions)}
-        r_pyramid: Dict[str, Tensor] = {res: r_pyramid[idx] for idx, res in enumerate(self.resolutions)}
-        net_pyramid: Dict[str, Tensor] = {res: net_pyramid[idx] for idx, res in enumerate(self.resolutions)}
-        ctx_pyramid: Dict[str, Tensor] = {res: ctx_pyramid[idx] for idx, res in enumerate(self.resolutions)}
+        l_pyramid = {res: l_pyramid[idx] for idx, res in enumerate(self.resolutions)}
+        r_pyramid = {res: r_pyramid[idx] for idx, res in enumerate(self.resolutions)}
+        net_pyramid = {res: net_pyramid[idx] for idx, res in enumerate(self.resolutions)}
+        ctx_pyramid = {res: ctx_pyramid[idx] for idx, res in enumerate(self.resolutions)}
 
         # offsets for sampling pixel candidates in the correlation ops
         offsets: Dict[str, Tensor] = {}
@@ -1425,6 +1425,9 @@ def crestereo_base(*, weights: Optional[CREStereo_Base_Weights] = None, progress
     .. autoclass:: torchvision.prototype.models.depth.stereo.CREStereo_Base_Weights
         :members:
     """
+
+    weights = CREStereo_Base_Weights.verify(weights)
+
     return _crestereo(
         weights=weights,
         progress=progress,