diff --git a/pika-build-config/lto.sh b/pika-build-config/lto.sh
index 52ebc63ff..9b6302aa4 100644
--- a/pika-build-config/lto.sh
+++ b/pika-build-config/lto.sh
@@ -1,5 +1,5 @@
-export PIKA_PACKAGE_VERSION="1.11.2-2"
-export PIKA_PACKAGE_NAME="mypy"
+export PIKA_PACKAGE_VERSION="1:19.1.0~++rc4-2"
+export PIKA_PACKAGE_NAME="llvm-toolchain-19"
 export PIKA_PACKAGE_PATCH=false
 export PIKA_REBUILD=false
 export PIKA_REBUILD_VERSION="b0"