diff --git a/lake-manifest.json b/lake-manifest.json
index 4150a6b8..ac4db7e1 100644
--- a/lake-manifest.json
+++ b/lake-manifest.json
@@ -85,7 +85,7 @@
   {"url": "https://github.com/leanprover-community/mathlib4.git",
    "type": "git",
    "subDir": null,
-   "rev": "23725d3c75b6d2eca0ec17d66cdc65ea9b924b47",
+   "rev": "124f27e89c4f233bc23e4c6418f3c632b7edc6a1",
    "name": "mathlib",
    "manifestFile": "lake-manifest.json",
    "inputRev": null,
diff --git a/lean-toolchain b/lean-toolchain
index 29c0cea4..64981ae5 100644
--- a/lean-toolchain
+++ b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:v4.9.0-rc2
+leanprover/lean4:v4.11.0-rc1