diff --git a/Ports/readline/package.sh b/Ports/readline/package.sh
index fc9f0e8a7d..4aa9625110 100755
--- a/Ports/readline/package.sh
+++ b/Ports/readline/package.sh
@@ -3,6 +3,7 @@
 port=readline
 version=8.1
 useconfigure=true
+config_sub_path=support/config.sub
 use_fresh_config_sub=true
 files="https://ftpmirror.gnu.org/gnu/readline/readline-${version}.tar.gz readline-${version}.tar.gz f8ceb4ee131e3232226a17f51b164afc46cd0b9e6cef344be87c65962cb82b02"
 auth_type=sha256