diff --git a/vllm/distributed/kv_transfer/kv_connector/v1/decode_bench_connector.py b/vllm/distributed/kv_transfer/kv_connector/v1/decode_bench_connector.py
index 6e9e757ffbd5..9a39ec658fff 100644
--- a/vllm/distributed/kv_transfer/kv_connector/v1/decode_bench_connector.py
+++ b/vllm/distributed/kv_transfer/kv_connector/v1/decode_bench_connector.py
@@ -40,7 +40,10 @@
     KVConnectorBase_V1,
     KVConnectorRole,
 )
-from vllm.distributed.kv_transfer.kv_connector.v1.base import KVConnectorMetadata
+from vllm.distributed.kv_transfer.kv_connector.v1.base import (
+    KVConnectorMetadata,
+    SupportsHMA,
+)
 from vllm.logger import init_logger
 from vllm.utils.math_utils import cdiv
 from vllm.v1.attention.backend import AttentionMetadata
@@ -71,7 +74,7 @@ class DecodeBenchConnectorMetadata(KVConnectorMetadata):
     reqs_to_fill: dict[str, tuple[tuple[list[int], ...], int]]
 
 
-class DecodeBenchConnector(KVConnectorBase_V1):
+class DecodeBenchConnector(KVConnectorBase_V1, SupportsHMA):
     """
     A KV Connector for decode instance performance testing.
 
@@ -164,6 +167,17 @@ def request_finished(
         self.connector_scheduler.request_finished(request)
         return False, None
 
+    def request_finished_all_groups(
+        self,
+        request: "Request",
+        block_ids: tuple[list[int], ...],
+    ) -> tuple[bool, dict[str, Any] | None]:
+        # HMA-enabled path: same cleanup as the single-group variant since
+        # this connector owns no external state per block.
+        assert self.connector_scheduler is not None
+        self.connector_scheduler.request_finished(request)
+        return False, None
+
 
 class DecodeBenchConnectorScheduler:
     """Scheduler-side implementation for DecodeBenchConnector."""