diff --git a/var/spack/repos/builtin/packages/ack/package.py b/var/spack/repos/builtin/packages/ack/package.py
index 41100a5e66d..af7d206c29a 100644
--- a/var/spack/repos/builtin/packages/ack/package.py
+++ b/var/spack/repos/builtin/packages/ack/package.py
@@ -43,9 +43,6 @@ class Ack(Package):
     # should:
     # depends_on('perl')
 
-    def unpack(self):
-        pass
-
     def install(self, spec, prefix):
         mkdirp(prefix.bin)
         ack = 'ack-{0}-single-file'.format(self.version)