diff --git a/artiq/frontend/artiq_master.py b/artiq/frontend/artiq_master.py
index 804c554d4..c9e7f6f86 100755
--- a/artiq/frontend/artiq_master.py
+++ b/artiq/frontend/artiq_master.py
@@ -41,7 +41,7 @@ def main():
     repository = Repository()
     explist = FlatFileDB("explist.pyon")
 
-    if os.name == 'nt':
+    if os.name == "nt":
         loop = asyncio.ProactorEventLoop()
         asyncio.set_event_loop(loop)
     else: