diff --git a/src/main/java/com/googlesource/gerrit/plugins/forcedraft/ForceDraft.java b/src/main/java/com/googlesource/gerrit/plugins/forcedraft/ForceDraft.java
index 712d587..7840751 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/forcedraft/ForceDraft.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/forcedraft/ForceDraft.java
@@ -54,7 +54,8 @@
   @Inject
   private @GerritServerConfig Config config;
 
-  @Argument(index = 0, required = true, usage = "<change, patch set> to be changed to draft")
+  @Argument(index = 0, required = true, metaVar = "{CHANGE,PATCHSET}",
+      usage = "<change, patch set> to be changed to draft")
   private void addPatchSetId(final String token) {
     try {
       patchSet = parsePatchSet(token);