diff --git a/Python/errors.c b/Python/errors.c
index 3c721b8ff64..0249fd99e98 100644
--- a/Python/errors.c
+++ b/Python/errors.c
@@ -194,5 +194,6 @@ err_errno(exc)
 void
 err_badcall()
 {
+	fatal("err_badcall() called");
 	err_setstr(SystemError, "bad argument to internal function");
 }