diff --git a/lake-manifest.json b/lake-manifest.json
index cd1b5e2..b9e528a 100644
--- a/lake-manifest.json
+++ b/lake-manifest.json
@@ -4,7 +4,7 @@
  [{"url": "https://github.com/leanprover-community/batteries",
    "type": "git",
    "subDir": null,
-   "rev": "6a63eb6a326181df29d95a84ce1f16c1145e66d8",
+   "rev": "15d42e1a92a80d0db5ca1c12123866ba392b9d76",
    "name": "batteries",
    "manifestFile": "lake-manifest.json",
    "inputRev": "main",
@@ -22,7 +22,7 @@
   {"url": "https://github.com/leanprover-community/aesop",
    "type": "git",
    "subDir": null,
-   "rev": "7e3bd939c6badfcb1e607c0fddb509548baafd05",
+   "rev": "882561b77bd2aaa98bd8665a56821062bdb3034c",
    "name": "aesop",
    "manifestFile": "lake-manifest.json",
    "inputRev": "master",
@@ -58,7 +58,7 @@
   {"url": "https://github.com/leanprover-community/mathlib4.git",
    "type": "git",
    "subDir": null,
-   "rev": "e16925c9357084ffff5de2715602e513ea01b518",
+   "rev": "03092720f68254315c95a5bf249c5f2cdef717d6",
    "name": "mathlib",
    "manifestFile": "lake-manifest.json",
    "inputRev": null,
@@ -94,7 +94,7 @@
   {"url": "https://github.com/leanprover/doc-gen4",
    "type": "git",
    "subDir": null,
-   "rev": "f50d2c1a6e07b55907b82913c2e82bfae34e9257",
+   "rev": "b61771aaa8f15bce5e3a38aebeb6dda487f4f29c",
    "name": "«doc-gen4»",
    "manifestFile": "lake-manifest.json",
    "inputRev": "main",
diff --git a/lean-toolchain b/lean-toolchain
index 0ba3faf..29c0cea 100644
--- a/lean-toolchain
+++ b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:v4.9.0-rc1
+leanprover/lean4:v4.9.0-rc2