diff --git a/setup.cfg b/setup.cfg
index af4550aa0a..2198e55434 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -2,6 +2,8 @@
 max-line-length = 160
 builtins = _,dynamic_property,__,P,I,lopen,icu_lower,icu_upper,icu_title,ngettext,connect_lambda
 ignore = E12,E203,E22,E231,E241,E401,E402,E731,W391,E722,E741,W504
+per-file-ignores =
+    src/polyglot/*:F401
 
 [yapf]
 based_on_style = pep8