diff --git a/pika-build-config/lto.sh b/pika-build-config/lto.sh
index 1e96955e5..76edf1726 100644
--- a/pika-build-config/lto.sh
+++ b/pika-build-config/lto.sh
@@ -1,5 +1,5 @@
-export PIKA_PACKAGE_VERSION="5.15.0+dfsg2-13"
-export PIKA_PACKAGE_NAME="plplot"
+export PIKA_PACKAGE_VERSION="2.9.1+dfsg-1"
+export PIKA_PACKAGE_NAME="ruby-json"
 export PIKA_PACKAGE_PATCH=false
 export PIKA_REBUILD=false
 export PIKA_REBUILD_VERSION="b0"