diff --git a/plugins/debian/debian.plugin.zsh b/plugins/debian/debian.plugin.zsh
index 55b90e379..7cd4902f6 100644
--- a/plugins/debian/debian.plugin.zsh
+++ b/plugins/debian/debian.plugin.zsh
@@ -6,14 +6,14 @@
 
 # Use aptitude if installed, or apt-get if not.
 # You can just set apt_pref='apt-get' to override it.
-if [[ -e $( which aptitude 2>&1 ) ]]; then
+if whence aptitude > /dev/null; then
     apt_pref='aptitude'
 else
     apt_pref='apt-get'
 fi
 
 # Use sudo by default if it's installed
-if [[ -e $( which sudo 2>&1 ) ]]; then
+if whence sudo > /dev/null; then
     use_sudo=1
 fi