diff --git a/.aliases b/.aliases
index 1d3e53b..aec6964 100644
--- a/.aliases
+++ b/.aliases
@@ -3,12 +3,12 @@ alias ll='ls -lihF'
 alias la='ls -A'
 alias l='ll -A'
 
-alias t='tree'
 alias sudo='sudo '
 alias grep='grep -n --color=auto'
 alias j='jobs'
 alias df='df -h'
 alias du='du -ch'
+hash tree 2>/dev/null && alias t='tree'
 hash htop 2>/dev/null && alias top='htop'
 hash xscreensaver-command 2>/dev/null && alias lock='xscreensaver-command --lock'
 hash sqlmap 2>/dev/null && alias sqlmap='sqlmap --user-agent="Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"'