diff --git a/src/_brew b/src/_brew
index d2b9277277..d7790aecdc 100644
--- a/src/_brew
+++ b/src/_brew
@@ -76,6 +76,7 @@ _brew_cask() {
     "install:installs the given Cask"
     "list:with no args, lists installed Casks; given installed Casks, lists staged files"
     "search:searches all known Casks"
+    "style:checks Cask style using RuboCop"
     "uninstall:uninstalls the given Cask"
     "update:a synonym for 'brew update'"
     "zap:zaps all files associated with the given Cask"