diff --git a/thefuck/rules/port_already_in_use.py b/thefuck/rules/port_already_in_use.py
index 43171d6..8264775 100644
--- a/thefuck/rules/port_already_in_use.py
+++ b/thefuck/rules/port_already_in_use.py
@@ -1,8 +1,10 @@
 import re
 from subprocess import Popen, PIPE
-from thefuck.utils import memoize
+from thefuck.utils import memoize, which
 from thefuck.shells import shell
 
+enabled_by_default = bool(which('lsof'))
+
 patterns = [r"bind on address \('.*', (?P<port>\d+)\)",
             r'Unable to bind [^ ]*:(?P<port>\d+)',
             r"can't listen on port (?P<port>\d+)",