diff --git a/tox.ini b/tox.ini
index e1cfc5bb..8596e66c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -19,4 +19,4 @@ deps =
 exclude = .tox,env,build,cocoalib,cocoa,help,./qt/dg_rc.py,cocoa/run_template.py,./pkg
 max-line-length = 120
 select = C,E,F,W,B,B950
-extend-ignore = E203, E501
+extend-ignore = E203, E501, W503