diff --git a/src/h3_blackwell_runtime/qwen3vl_vision.py b/src/h3_blackwell_runtime/qwen3vl_vision.py
index 90eebb5..05eae4c 100644
--- a/src/h3_blackwell_runtime/qwen3vl_vision.py
+++ b/src/h3_blackwell_runtime/qwen3vl_vision.py
@@ -340,7 +340,16 @@ def resize_keyframe(image: torch.Tensor, width: int, height: int, *, crop: str =
         elif old_aspect < new_aspect:
             y = round((old_h - old_h * (old_aspect / new_aspect)) / 2)
         samples = samples.narrow(-2, y, old_h - 2 * y).narrow(-1, x, old_w - 2 * x)
-    samples = F.interpolate(samples, size=(height, width), mode="lanczos")
+    # F.interpolate(4D, lanczos) is not supported by PyTorch; emulate via
+    # upsample-then-downsample with nearest + a small Lanczos-3 kernel.
+    # (Simpler: just use PIL's LANCZOS via numpy for the single image.)
+    import numpy as np
+    from PIL import Image as PILImage
+    arr = samples[0].permute(1, 2, 0).cpu().numpy()  # [H, W, 3]
+    arr = (arr * 255.0).astype(np.uint8)
+    img = PILImage.fromarray(arr, mode="RGB")
+    img = img.resize((width, height), PILImage.LANCZOS)
+    samples = torch.from_numpy(np.asarray(img).astype(np.float32) / 255.0).permute(2, 0, 1).unsqueeze(0)
     return samples.clamp(0.0, 1.0).movedim(1, -1)  # [1, H, W, 3]