diff --git a/setup.cfg b/setup.cfg
index a2175f03..eda7a527 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,3 +1,7 @@
+# Please keep all characters in this file in ASCII
+# distutils uses system's locale to interpret it and not everybody
+# uses UTF-8. See https://github.com/httpie/httpie/issues/1039
+# for an example
 [wheel]