diff --git a/malcontent-client/docs/malcontent-client.8 b/malcontent-client/docs/malcontent-client.8
index 917adb7..cfc3c6d 100644
--- a/malcontent-client/docs/malcontent-client.8
+++ b/malcontent-client/docs/malcontent-client.8
@@ -26,6 +26,9 @@ It communicates with accounts-service, which stores parental controls data.
 .PP
 Its first argument is a command to run. Currently, the only supported commands
 are \fBget\-app\-filter\fP and \fBcheck\-app\-filter\fP.
+.PP
+The command line API and output format are unstable and likely to change in
+future versions of \fBmalcontent\-client\fP.
 .\"
 .SH \fBget\-app\-filter\fP OPTIONS
 .IX Header "get\-app\-filter OPTIONS"