diff --git a/README.md b/README.md
index 21a50b2..e3c6988 100644
--- a/README.md
+++ b/README.md
@@ -95,3 +95,7 @@ Putting it in a directory that is only readable by the super-user is not a bad i
 ## Filtering
 
 Domains can be filtered directly by the proxy, see the `[filtering]` section of the configuration file.
+
+## Prometheus metrics
+
+Prometheus metrics can optionally be enabled in order to monitor performance, cache efficiency, and more.