1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index 109b1e2fb5..9ffd23c6df 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -141,7 +141,7 @@ def start_reactor(
 
 def quit_with_error(error_string):
     message_lines = error_string.split("\n")
-    line_length = max([len(l) for l in message_lines if len(l) < 80]) + 2
+    line_length = max(len(l) for l in message_lines if len(l) < 80) + 2
     sys.stderr.write("*" * line_length + "\n")
     for line in message_lines:
         sys.stderr.write(" %s\n" % (line.rstrip(),))