diff --git a/pkgs/development/python-modules/prometheus_client/default.nix b/pkgs/development/python-modules/prometheus_client/default.nix
index 8f608666d720..e4cf4e85af0f 100644
--- a/pkgs/development/python-modules/prometheus_client/default.nix
+++ b/pkgs/development/python-modules/prometheus_client/default.nix
@@ -2,11 +2,11 @@
 
 buildPythonPackage rec {
   pname = "prometheus_client";
-  version = "0.8.0";
+  version = "0.9.0";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "c6e6b706833a6bd1fd51711299edee907857be10ece535126a158f911ee80915";
+    sha256 = "9da7b32f02439d8c04f7777021c304ed51d9ec180604700c1ba72a4d44dceb03";
   };
 
   doCheck = false;