diff --git a/pika-build-config/lto.sh b/pika-build-config/lto.sh
index 884228153..2e422a98b 100644
--- a/pika-build-config/lto.sh
+++ b/pika-build-config/lto.sh
@@ -1,5 +1,5 @@
-export PIKA_PACKAGE_VERSION="1.7.3-pre5-12"
-export PIKA_PACKAGE_NAME="xsystem35"
+export PIKA_PACKAGE_VERSION="0.6.3-1"
+export PIKA_PACKAGE_NAME="ocaml-rope"
 export PIKA_PACKAGE_PATCH=false
 export PIKA_REBUILD=false
 export PIKA_REBUILD_VERSION="b0"