diff --git a/var/spack/repos/builtin/packages/unison/package.py b/var/spack/repos/builtin/packages/unison/package.py
index 15c57db6653..181e1e6410e 100644
--- a/var/spack/repos/builtin/packages/unison/package.py
+++ b/var/spack/repos/builtin/packages/unison/package.py
@@ -41,6 +41,7 @@ class Unison(Package):
     depends_on('ocaml', type='build')
 
     parallel = False
+
     def install(self, spec, prefix):
         make('./mkProjectInfo')
         make('UISTYLE=text')