diff --git a/src/eva/metrics/accuracy/faithfulness.py b/src/eva/metrics/accuracy/faithfulness.py
index 7b885d21..250eb36b 100644
--- a/src/eva/metrics/accuracy/faithfulness.py
+++ b/src/eva/metrics/accuracy/faithfulness.py
@@ -60,6 +60,7 @@ class FaithfulnessJudgeMetric(ConversationTextJudgeMetric):
     )
     category = "accuracy"
     default_model = "us.anthropic.claude-opus-4-6-v1"
+    default_params = {"max_tokens": 100000}  # Drop the OpenAI-only flex tier inherited from TextJudgeMetric.
     rating_scale = (1, 3)
 
     def get_prompt_variables(self, context: MetricContext, transcript_text: str) -> dict[str, Any]:
diff --git a/src/eva/metrics/base.py b/src/eva/metrics/base.py
index ca15d8b6..1f8d6ce7 100644
--- a/src/eva/metrics/base.py
+++ b/src/eva/metrics/base.py
@@ -330,7 +330,7 @@ class TextJudgeMetric(BaseMetric):
 
     # Subclasses can override these
     default_model = "gpt-5.2"
-    default_params: dict[str, Any] = {"max_tokens": 100000}
+    default_params: dict[str, Any] = {"max_tokens": 100000, "service_tier": "flex"}
     rating_scale: tuple[int, int] = (1, 3)  # (min, max)
 
     def __init__(self, config: dict[str, Any] | None = None):
diff --git a/tests/fixtures/metric_signatures.json b/tests/fixtures/metric_signatures.json
index 992ac39b..043e80b3 100644
--- a/tests/fixtures/metric_signatures.json
+++ b/tests/fixtures/metric_signatures.json
@@ -8,7 +8,7 @@
   "ConcisenessJudgeMetric": {
     "name": "conciseness",
     "prompt_hash": "57caf9a18a3c",
-    "source_hash": "e39cacd719a2",
+    "source_hash": "9f183871e45a",
     "version": "v0.1"
   },
   "ConversationCorrectlyFinishedMetric": {
@@ -20,7 +20,7 @@
   "ConversationProgressionJudgeMetric": {
     "name": "conversation_progression",
     "prompt_hash": "174cdf93b398",
-    "source_hash": "8d1a32e8a4fe",
+    "source_hash": "4e5f59c32946",
     "version": "v0.1"
   },
   "ConversationTimeLimitExceededMetric": {
@@ -38,7 +38,7 @@
   "FaithfulnessJudgeMetric": {
     "name": "faithfulness",
     "prompt_hash": "060e3f1f9e7a",
-    "source_hash": "7db40c133d8a",
+    "source_hash": "93a559d0a028",
     "version": "v0.2"
   },
   "ResponseSpeedMetric": {
@@ -56,7 +56,7 @@
   "SpeakabilityJudgeMetric": {
     "name": "speakability",
     "prompt_hash": "1e4f78cb051e",
-    "source_hash": "dd4feece62c1",
+    "source_hash": "c8a781f5795b",
     "version": "v0.2"
   },
   "SpeechFidelityMetric": {
@@ -86,7 +86,7 @@
   "TranscriptionAccuracyKeyEntitiesMetric": {
     "name": "transcription_accuracy_key_entities",
     "prompt_hash": "aa1a7fdd6df7",
-    "source_hash": "80a4d892e1f6",
+    "source_hash": "96271903ded0",
     "version": "v0.2"
   },
   "TurnTakingMetric": {
@@ -98,7 +98,7 @@
   "UserBehavioralFidelityMetric": {
     "name": "user_behavioral_fidelity",
     "prompt_hash": "21527fa8d79b",
-    "source_hash": "fded1ad48aa4",
+    "source_hash": "7f5dcec51568",
     "version": "v0.1"
   },
   "UserSpeechFidelityMetric": {