diff --git a/pika-build-config/lto.sh b/pika-build-config/lto.sh
index c2a734b94..181b3a889 100644
--- a/pika-build-config/lto.sh
+++ b/pika-build-config/lto.sh
@@ -1,5 +1,5 @@
-export PIKA_PACKAGE_VERSION="7.1.0-1"
-export PIKA_PACKAGE_NAME="zope.interface"
+export PIKA_PACKAGE_VERSION="5.0b-2"
+export PIKA_PACKAGE_NAME="fairymax"
 export PIKA_PACKAGE_PATCH=false
 export PIKA_REBUILD=false
 export PIKA_REBUILD_VERSION="b0"