diff --git a/doc/cli.markdown b/doc/cli.markdown
index e8234e16..2cd5e0bb 100644
--- a/doc/cli.markdown
+++ b/doc/cli.markdown
@@ -1525,6 +1525,9 @@ Example:
 Use this command to download an unconfigured os image for a certain device type.
 Check available types with `balena devices supported`
 
+> Note: Currently this command only works with balenaCloud, not openBalena.
+> If using openBalena, please download the OS from: https://www.balena.io/os/
+
 If version is not specified the newest stable (non-pre-release) version of OS
 is downloaded if available, or the newest version otherwise (if all existing
 versions for the given device type are pre-release).
diff --git a/lib/actions/os.js b/lib/actions/os.js
index 01e3f948..1b99b2da 100644
--- a/lib/actions/os.js
+++ b/lib/actions/os.js
@@ -86,6 +86,9 @@ export const download = {
 Use this command to download an unconfigured os image for a certain device type.
 Check available types with \`balena devices supported\`
 
+> Note: Currently this command only works with balenaCloud, not openBalena.
+> If using openBalena, please download the OS from: https://www.balena.io/os/
+
 If version is not specified the newest stable (non-pre-release) version of OS
 is downloaded if available, or the newest version otherwise (if all existing
 versions for the given device type are pre-release).