diff --git a/requirements-ci.txt b/requirements-ci.txt
index b7717cf..842bb33 100644
--- a/requirements-ci.txt
+++ b/requirements-ci.txt
@@ -19,7 +19,7 @@ cbor2>=5.4.0
 fastapi>=0.109.0
 uvicorn[standard]>=0.27.0
 pydantic>=2.5.0
-prometheus-client>=0.20.0
+prometheus-client>=0.26.0
 
 # Test-only: starlette's TestClient (used by tests/server/test_rest_api.py)
 # imports httpx at module load; without it that test module fails to collect.
diff --git a/requirements.txt b/requirements.txt
index 5c713ee..799cd54 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -37,7 +37,7 @@ cbor2>=5.4.0
 fastapi>=0.109.0
 uvicorn[standard]>=0.27.0
 pydantic>=2.5.0
-prometheus-client>=0.20.0
+prometheus-client>=0.26.0
 
 # OPTIONAL: RSWP swap-order signature verification (C3-auth, Part B).
 # Only needed when SWAP_VERIFY_SIGNATURES is enabled — the indexer runs fine