diff --git a/documentation/prometheus-mixin/Makefile b/documentation/prometheus-mixin/Makefile
index 8319b5edf9..9ade5aa2b6 100644
--- a/documentation/prometheus-mixin/Makefile
+++ b/documentation/prometheus-mixin/Makefile
@@ -1,4 +1,4 @@
-JSONNET_FMT := jsonnet fmt -n 2 --max-blank-lines 2 --string-style s --comment-style s
+JSONNET_FMT := jsonnetfmt -n 2 --max-blank-lines 2 --string-style s --comment-style s
 
 all: fmt prometheus_alerts.yaml dashboards_out lint
 
diff --git a/documentation/prometheus-mixin/README.md b/documentation/prometheus-mixin/README.md
index 1cb009f683..7f211b2553 100644
--- a/documentation/prometheus-mixin/README.md
+++ b/documentation/prometheus-mixin/README.md
@@ -3,16 +3,18 @@
 The Prometheus Mixin is a set of configurable, reusable, and extensible alerts
 and dashboards for Prometheus.
 
-To use them, you need to have `jsonnet` (v0.10+) and `jb` installed. If you
+To use them, you need to have `jsonnet` (v0.13+) and `jb` installed. If you
 have a working Go development environment, it's easiest to run the following:
 ```bash
 $ go get github.com/google/go-jsonnet/cmd/jsonnet
 $ go get github.com/jsonnet-bundler/jsonnet-bundler/cmd/jb
 ```
 
-_Note: The make targets `lint` and `fmt` currently don't work with the Go
-implementation of `jsonnet`. For the time being, you have to install the [C++
-version of jsonnet](https://github.com/google/jsonnet) if you want to use them._
+_Note: The make targets `lint` and `fmt` need the `jsonnetfmt` binary, which is
+currently not included in the Go implementation of `jsonnet`. For the time
+being, you have to install the [C++ version of
+jsonnetfmt](https://github.com/google/jsonnet) if you want to use `make lint`
+or `make fmt`._
 
 Next, install the dependencies by running the following command in this
 directory: