diff --git a/cli_reference/opm/cli-opm-ref.adoc b/cli_reference/opm/cli-opm-ref.adoc
index a45b57f1fe..fdb291fb46 100644
--- a/cli_reference/opm/cli-opm-ref.adoc
+++ b/cli_reference/opm/cli-opm-ref.adoc
@@ -14,6 +14,11 @@ The `opm` command-line interface (CLI) is a tool for creating and maintaining Op
 $ opm <command> [<subcommand>] [<argument>] [<flags>]
 ----
 
+[WARNING]
+====
+The `opm` CLI is not forward compatible. The version of the `opm` CLI used to generate catalog content must be earlier than or equal to the version used to serve the content on a cluster.
+====
+
 .Global flags
 [options="header",cols="1,3"]
 |===
@@ -46,4 +51,4 @@ include::modules/opm-cli-ref-init.adoc[leveloffset=+1]
 include::modules/opm-cli-ref-migrate.adoc[leveloffset=+1]
 include::modules/opm-cli-ref-render.adoc[leveloffset=+1]
 include::modules/opm-cli-ref-serve.adoc[leveloffset=+1]
-include::modules/opm-cli-ref-validate.adoc[leveloffset=+1]
\ No newline at end of file
+include::modules/opm-cli-ref-validate.adoc[leveloffset=+1]