diff --git a/ultralytics/engine/trainer.py b/ultralytics/engine/trainer.py
index b8d917ce8..f344b157b 100644
--- a/ultralytics/engine/trainer.py
+++ b/ultralytics/engine/trainer.py
@@ -210,7 +210,7 @@ class BaseTrainer:
         torch.cuda.set_device(RANK)
         self.device = torch.device("cuda", RANK)
         # LOGGER.info(f'DDP info: RANK {RANK}, WORLD_SIZE {world_size}, DEVICE {self.device}')
-        os.environ["NCCL_BLOCKING_WAIT"] = "1"  # set to enforce timeout
+        os.environ["TORCH_NCCL_BLOCKING_WAIT"] = "1"  # set to enforce timeout
         dist.init_process_group(
             "nccl" if dist.is_nccl_available() else "gloo",
             timeout=timedelta(seconds=10800),  # 3 hours