diff --git a/litellm/types/integrations/prometheus.py b/litellm/types/integrations/prometheus.py
index f9e50ff0f4..6fe859370c 100644
--- a/litellm/types/integrations/prometheus.py
+++ b/litellm/types/integrations/prometheus.py
@@ -1,5 +1,5 @@
 import re
-from dataclasses import dataclass, field, fields
+from dataclasses import MISSING, dataclass, field, fields
 from enum import Enum
 from types import MappingProxyType
 from typing import Any, ClassVar, Dict, List, Literal, Mapping, Optional, Tuple, Union
@@ -743,7 +743,13 @@ class PrometheusMetricLabels:
         return default_labels + custom_labels
 
 
-@dataclass(frozen=True)
+_USER_API_KEY_LABEL_VALUE_INIT_ALIASES: Dict[str, str] = {
+    # Some tests / call sites use ``api_key_hash``; Prometheus field is ``hashed_api_key``.
+    "api_key_hash": "hashed_api_key",
+}
+
+
+@dataclass(frozen=True, init=False)
 class UserAPIKeyLabelValues:
     """
     Prometheus metric label inputs (Python field names match historical Pydantic ``model_dump`` keys).
@@ -780,6 +786,31 @@ class UserAPIKeyLabelValues:
     org_id: Optional[str] = None
     org_alias: Optional[str] = None
 
+    def __init__(self, **kwargs: Any) -> None:
+        """
+        Match former Pydantic behavior: unknown keys are ignored; ``api_key_hash`` maps to
+        ``hashed_api_key``. This supports ``**standard_logging_payload`` in tests.
+        """
+        field_names = {f.name for f in fields(self)}
+        merged: Dict[str, Any] = {}
+        for f in fields(self):
+            if f.default_factory is not MISSING:
+                merged[f.name] = f.default_factory()
+            else:
+                merged[f.name] = f.default
+
+        for k, v in kwargs.items():
+            if k in field_names:
+                merged[k] = v
+                continue
+            canon = _USER_API_KEY_LABEL_VALUE_INIT_ALIASES.get(k)
+            if canon is not None and canon in field_names:
+                merged[canon] = v
+
+        for f in fields(self):
+            object.__setattr__(self, f.name, merged[f.name])
+        self.__post_init__()
+
     def __post_init__(self) -> None:
         object.__setattr__(self, "tags", tuple(self.tags))
         if self.stream is not None:
diff --git a/tests/enterprise/litellm_enterprise/enterprise_callbacks/test_prometheus_logging_callbacks.py b/tests/enterprise/litellm_enterprise/enterprise_callbacks/test_prometheus_logging_callbacks.py
index 8fa56029f4..d3f7d882da 100644
--- a/tests/enterprise/litellm_enterprise/enterprise_callbacks/test_prometheus_logging_callbacks.py
+++ b/tests/enterprise/litellm_enterprise/enterprise_callbacks/test_prometheus_logging_callbacks.py
@@ -660,7 +660,7 @@ async def test_async_log_failure_event(prometheus_logger):
     )
 
     # litellm_llm_api_failed_requests_metric incremented
-    # Labels: end_user, api_key_hash, api_key_alias, model, team, team_alias, user, model_id
+    # Labels: end_user, hashed_api_key, api_key_alias, model, team, team_alias, user, model_id
     prometheus_logger.litellm_llm_api_failed_requests_metric.labels.assert_called_once_with(
         None,  # end_user_id
         "test_hash",
@@ -1150,10 +1150,10 @@ def test_prometheus_factory(monkeypatch, enable_end_user_cost_tracking_prometheu
 
     enum_values = UserAPIKeyLabelValues(
         end_user="test_end_user",
-        api_key_hash="test_hash",
+        hashed_api_key="test_hash",
         api_key_alias="test_alias",
     )
-    supported_labels = ["end_user", "api_key_hash", "api_key_alias"]
+    supported_labels = ["end_user", "hashed_api_key", "api_key_alias"]
     returned_dict = prometheus_label_factory(
         supported_enum_labels=supported_labels, enum_values=enum_values
     )
@@ -1162,6 +1162,8 @@ def test_prometheus_factory(monkeypatch, enable_end_user_cost_tracking_prometheu
         assert returned_dict["end_user"] == "test_end_user"
     else:
         assert returned_dict["end_user"] == None
+    assert returned_dict["hashed_api_key"] == "test_hash"
+    assert returned_dict["api_key_alias"] == "test_alias"
 
 
 def test_get_custom_labels_from_metadata(monkeypatch):