diff --git a/ultralytics/engine/exporter.py b/ultralytics/engine/exporter.py
index df136c14..2cf3d26c 100644
--- a/ultralytics/engine/exporter.py
+++ b/ultralytics/engine/exporter.py
@@ -1556,8 +1556,8 @@ class NMSModel(torch.nn.Module):
         preds = self.model(x)
         pred = preds[0] if isinstance(preds, tuple) else preds
         pred = pred.transpose(-1, -2)  # shape(1,84,6300) to shape(1,6300,84)
-        extra_shape = pred.shape[-1] - (4 + self.model.nc)  # extras from Segment, OBB, Pose
-        boxes, scores, extras = pred.split([4, self.model.nc, extra_shape], dim=2)
+        extra_shape = pred.shape[-1] - (4 + len(self.model.names))  # extras from Segment, OBB, Pose
+        boxes, scores, extras = pred.split([4, len(self.model.names), extra_shape], dim=2)
         scores, classes = scores.max(dim=-1)
         self.args.max_det = min(pred.shape[1], self.args.max_det)  # in case num_anchors < max_det
         # (N, max_det, 4 coords + 1 class score + 1 class label + extra_shape).