diff --git a/web/ui/react-app/public/index.html b/web/ui/react-app/public/index.html
index a3f7b7a850..57131a26b6 100755
--- a/web/ui/react-app/public/index.html
+++ b/web/ui/react-app/public/index.html
@@ -16,10 +16,14 @@
- PROMETHEUS_AGENT_MODE is replaced by a boolean indicating if Prometheus is running in agent mode.
It true, it will disable querying capacities in the UI and generally adapt the UI to the agent mode.
It has to be represented as a string, because booleans can be mangled to !1 in production builds.
+ - PROMETHEUS_READY is replaced by a boolean indicating whether Prometheus was ready at the time the
+ web app was served. It has to be represented as a string, because booleans can be mangled to !1 in
+ production builds.
-->