--- a/python/mozboot/mozboot/osx.py
+++ b/python/mozboot/mozboot/osx.py
@@ -383,16 +383,17 @@ class OSXBootstrapper(BaseBootstrapper):
         missing = [package for package in packages if package not in installed]
         if missing:
             print(PACKAGE_MANAGER_PACKAGES % ('MacPorts',))
             self.run_as_root([self.port, '-v', 'install'] + missing)
 
     def ensure_macports_system_packages(self):
         packages = [
             'python27',
+            'py27-readline',
             'mercurial',
             'autoconf213',
             'gnutar',
             'watchman',
         ]
 
         self._ensure_macports_packages(packages)
         self.run_as_root([self.port, 'select', '--set', 'python', 'python27'])