diff --git a/comfy/ldm/depth_anything_3/transform.py b/comfy/ldm/depth_anything_3/transform.py
index f3ce8f6be..3f5541412 100644
--- a/comfy/ldm/depth_anything_3/transform.py
+++ b/comfy/ldm/depth_anything_3/transform.py
@@ -165,6 +165,9 @@ def pose_encoding_to_extri_intri(
     quat = pose_encoding[..., 3:7]
     fov_h = pose_encoding[..., 7]
     fov_w = pose_encoding[..., 8]
+    # Normalize to unit quaternion. CameraDec outputs raw values; a near-zero
+    # quaternion causes two_s = 2/norm² → inf in quat_to_mat → NaN extrinsics.
+    quat = quat / quat.norm(dim=-1, keepdim=True).clamp(min=1e-6)
     R = quat_to_mat(quat)
     extrinsics = torch.cat([R, T[..., None]], dim=-1)
     H, W = image_size_hw