diff --git a/setup.cfg b/setup.cfg
index 7c9cd4987..315984f49 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -157,6 +157,7 @@ disallow_any_generics = false
 follow_imports = silent
 ignore_missing_imports = true
 strict = true
+strict_bytes = true
 warn_unreachable = true
 
 # TODO: update our output assertions to match a new syntax