diff --git a/all_repos/sed.py b/all_repos/sed.py
index d5f8d10..81a028d 100644
--- a/all_repos/sed.py
+++ b/all_repos/sed.py
@@ -17,13 +17,13 @@
 from all_repos.config import Config
 from all_repos.util import zsplit
 
-SED_EXEC = "sed"
+SED_EXEC = 'sed'
 if platform.system() == 'Darwin':  # pragma: no cover
-    if not shutil.which("gsed"):
+    if not shutil.which('gsed'):
         print('MacOS specific prerequisite missing, please install it with: brew install gnu-sed')
         sys.exit(2)
 
-    SED_EXEC = "gsed"
+    SED_EXEC = 'gsed'
 
 
 def find_repos(