diff --git a/pika-build-config/lto.sh b/pika-build-config/lto.sh
index b750cb1a9..b011770dc 100644
--- a/pika-build-config/lto.sh
+++ b/pika-build-config/lto.sh
@@ -1,5 +1,5 @@
-export PIKA_PACKAGE_VERSION="6.12um1"
-export PIKA_PACKAGE_NAME="user-mode-linux"
+export PIKA_PACKAGE_VERSION="19.0.0-4"
+export PIKA_PACKAGE_NAME="magnum"
 export PIKA_PACKAGE_PATCH=false
 export PIKA_REBUILD=false
 export PIKA_REBUILD_VERSION="b0"