diff --git a/pyproject.toml b/pyproject.toml
index 28566f6..30605ea 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -27,7 +27,7 @@ requires-python = ">=3.9"
 dynamic = ["version"]
 dependencies = [
   "vllm>=0.6.2",
-  "prometheus_client==0.20.0",
+  "prometheus_client==0.21.0",
   "grpcio==1.62.2",
   "grpcio-health-checking==1.62.2",
   "grpcio-reflection==1.62.2",