diff --git a/flake.nix b/flake.nix
index 1343469..6484c09 100644
--- a/flake.nix
+++ b/flake.nix
@@ -30,6 +30,7 @@
 
               propagatedBuildInputs = [
                 paho-mqtt
+                prometheus-client
                 psutil
                 setuptools
               ];