diff --git a/python/sglang/srt/managers/router/model_runner.py b/python/sglang/srt/managers/router/model_runner.py
index 363289f73..d5f120418 100644
--- a/python/sglang/srt/managers/router/model_runner.py
+++ b/python/sglang/srt/managers/router/model_runner.py
@@ -19,7 +19,11 @@ from vllm.model_executor.layers.quantization.marlin import MarlinConfig
 from vllm.model_executor.model_loader import _set_default_torch_dtype
 from vllm.model_executor.parallel_utils.parallel_state import initialize_model_parallel
 
-QUANTIONCONFIG_MAPPING = {"awq": AWQConfig, "gptq": GPTQConfig, "marlin": MarlinConfig}
+QUANTIZATION_CONFIG_MAPPING = {
+    "awq": AWQConfig,
+    "gptq": GPTQConfig,
+    "marlin": MarlinConfig,
+}
 
 logger = logging.getLogger("model_runner")
 
@@ -300,30 +304,31 @@ class ModelRunner:
 
         # Load weights
         linear_method = None
+
+        quant_cfg = getattr(self.model_config.hf_config, "quantization_config", None)
+        if quant_cfg is not None:
+            quant_method = quant_cfg.get("quant_method", "").lower()
+            # compat: autogptq >=0.8.0 use checkpoint_format: str
+            # compat: autogptq <=0.7.1 is_marlin_format: bool
+            is_format_marlin = quant_cfg.get(
+                "checkpoint_format"
+            ) == "marlin" or quant_cfg.get("is_marlin_format", False)
+
+            # Use marlin if the GPTQ model is serialized in marlin format.
+            if quant_method == "gptq" and is_format_marlin:
+                quant_method = "marlin"
+
+            quant_config_class = QUANTIZATION_CONFIG_MAPPING.get(quant_method)
+
+            if quant_config_class is None:
+                raise ValueError(f"Unsupported quantization method: {quant_method}")
+
+            quant_config = quant_config_class.from_config(quant_cfg)
+            logger.info(f"quant_config: {quant_config}")
+            linear_method = quant_config.get_linear_method()
+
         with _set_default_torch_dtype(torch.float16):
             with torch.device("cuda"):
-                hf_quant_config = getattr(
-                    self.model_config.hf_config, "quantization_config", None
-                )
-                if hf_quant_config is not None:
-                    hf_quant_method = hf_quant_config["quant_method"]
-
-                    # compat: autogptq uses is_marlin_format within quant config
-                    if (
-                        hf_quant_method == "gptq"
-                        and "is_marlin_format" in hf_quant_config
-                        and hf_quant_config["is_marlin_format"]
-                    ):
-                        hf_quant_method = "marlin"
-                    quant_config_class = QUANTIONCONFIG_MAPPING.get(hf_quant_method)
-
-                    if quant_config_class is None:
-                        raise ValueError(
-                            f"Unsupported quantization method: {hf_quant_config['quant_method']}"
-                        )
-                    quant_config = quant_config_class.from_config(hf_quant_config)
-                    logger.info(f"quant_config: {quant_config}")
-                    linear_method = quant_config.get_linear_method()
                 model = model_class(
                     config=self.model_config.hf_config, linear_method=linear_method
                 )