diff --git a/pika-build-config/lto.sh b/pika-build-config/lto.sh
index cc8283a3e..f6fd02e03 100644
--- a/pika-build-config/lto.sh
+++ b/pika-build-config/lto.sh
@@ -1,5 +1,5 @@
-export PIKA_PACKAGE_VERSION="15.1.0-2"
-export PIKA_PACKAGE_NAME="ocaml-uucd"
+export PIKA_PACKAGE_VERSION="1.6.9-4"
+export PIKA_PACKAGE_NAME="cppo"
 export PIKA_PACKAGE_PATCH=false
 export PIKA_REBUILD=false
 export PIKA_REBUILD_VERSION="b0"