diff --git a/lean-toolchain b/lean-toolchain
index 2b8321730..a0ee52ef7 100644
--- a/lean-toolchain
+++ b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:nightly-2026-09-03
+leanprover/lean4-pr-releases:pr-release-15027-1ed4f9a