diff --git a/pytorch_optimizer/__init__.py b/pytorch_optimizer/__init__.py
index 3e9f25852..236b55d25 100644
--- a/pytorch_optimizer/__init__.py
+++ b/pytorch_optimizer/__init__.py
@@ -245,7 +245,7 @@ def load_optimizer(optimizer: str) -> OPTIMIZER:
 
     if optimizer.startswith('bnb'):
         if HAS_BNB and torch.cuda.is_available():
-            return load_bnb_optimizer(optimizer)
+            return load_bnb_optimizer(optimizer)  # pragma: no cover
         raise ImportError(f'[-] bitsandbytes and CUDA required for bnb optimizers : {optimizer}')
     if optimizer not in OPTIMIZERS:
         raise NotImplementedError(f'[-] not implemented optimizer : {optimizer}')