diff --git a/pika-build-config/lto.sh b/pika-build-config/lto.sh
index 12bd55c5b..03df89465 100644
--- a/pika-build-config/lto.sh
+++ b/pika-build-config/lto.sh
@@ -1,5 +1,5 @@
-export PIKA_PACKAGE_VERSION="0.4.1+ds-2"
-export PIKA_PACKAGE_NAME="python-serializable"
+export PIKA_PACKAGE_VERSION="4.0.2+dfsg-1"
+export PIKA_PACKAGE_NAME="python-signxml"
 export PIKA_PACKAGE_PATCH=false
 export PIKA_REBUILD=false
 export PIKA_REBUILD_VERSION="b0"