diff --git a/bin/cask-tidy b/bin/cask-tidy
index 4c6eb9b..ff20feb 100755
--- a/bin/cask-tidy
+++ b/bin/cask-tidy
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-[ ! -x $(which brew) -a ! -d /opt/homebrew-cask ] && exit 1
+[ ! -x "$(which brew 2>/dev/null)" -a ! -d /opt/homebrew-cask ] && exit 1
 
 function __remove-cask {
     caskBasePath="/opt/homebrew-cask/Caskroom"