diff --git a/python/sglang/srt/layers/quantization/modelopt_quant.py b/python/sglang/srt/layers/quantization/modelopt_quant.py
index ca1429f4bee..38f2e7b2d4e 100644
--- a/python/sglang/srt/layers/quantization/modelopt_quant.py
+++ b/python/sglang/srt/layers/quantization/modelopt_quant.py
@@ -12,6 +12,7 @@
     requantize_with_max_scale,
 )
 
+from sglang.srt.layers.attention import AttentionBackend
 from sglang.srt.layers.linear import LinearBase, LinearMethodBase
 from sglang.srt.layers.parameter import ModelWeightParameter, PerTensorScaleParameter
 from sglang.srt.layers.quantization.base_config import (
@@ -71,12 +72,12 @@ def from_config(cls, config: Dict[str, Any]) -> "ModelOptFp8Config":
     def get_quant_method(
         self, layer: torch.nn.Module, prefix: str
     ) -> Optional["QuantizeMethodBase"]:
-        from vllm.attention.layer import Attention
 
         if isinstance(layer, LinearBase):
             return ModelOptFp8LinearMethod(self)
-        elif isinstance(layer, Attention):
+        if isinstance(layer, AttentionBackend):
             return ModelOptFp8KVCacheMethod(self)
+
         return None
 
     def get_scaled_act_names(self) -> List[str]:
@@ -182,7 +183,7 @@ def apply(
 
 class ModelOptFp8KVCacheMethod(BaseKVCacheMethod):
     """
-    Supports loading kv-cache scaling factors from FP8 checkpoints.
+    Handles loading FP8 kv-cache scaling factors from modelopt quantized checkpoints.
     """
 
     def __init__(self, quant_config: ModelOptFp8Config):