diff --git a/vllm/config/vllm.py b/vllm/config/vllm.py
index c3f689c0a9c..8f90bb23326 100644
--- a/vllm/config/vllm.py
+++ b/vllm/config/vllm.py
@@ -1936,12 +1936,21 @@ class VllmConfig:
         if architecture is None:
             return
 
+        from vllm.model_executor.models import ModelRegistry
         from vllm.model_executor.models.config import (
             MODELS_CONFIG_MAP,
             HybridAttentionMambaModelConfig,
         )
 
         cls = MODELS_CONFIG_MAP.get(architecture, None)
+        if cls is None:
+            # `architecture` may be an HF base-model name (e.g. "Mamba2Model"
+            # when `architectures` is omitted); normalize to the resolved arch
+            # so per-arch config hooks are not skipped.
+            architecture = ModelRegistry._normalize_arch(
+                architecture, self.model_config
+            )
+            cls = MODELS_CONFIG_MAP.get(architecture, None)
         if cls is not None:
             cls.verify_and_update_config(self)