diff --git a/content/en/docs/setup/upgrade/index.md b/content/en/docs/setup/upgrade/index.md
index 98d845a719..44bbad4717 100644
--- a/content/en/docs/setup/upgrade/index.md
+++ b/content/en/docs/setup/upgrade/index.md
@@ -176,6 +176,10 @@ If you're using automatic sidecar injection, you can upgrade the sidecar
 by doing a rolling update for all the pods, so that the new version of the
 sidecar will be automatically re-injected.
 
+{{< warning >}}
+Your `kubectl` version must be >= 1.15 to run the following command. Upgrade if necessary.
+{{< /warning >}}
+
 {{< text bash >}}
 $ kubectl rollout restart deployment --namespace default
 {{< /text >}}