diff --git a/lake-manifest.json b/lake-manifest.json
index 442099d..aa83d7a 100644
--- a/lake-manifest.json
+++ b/lake-manifest.json
@@ -10,7 +10,7 @@
   {"git":
    {"url": "https://github.com/leanprover/lake",
     "subDir?": null,
-    "rev": "f120dbcaf8dafe864a5a4c28b34500352dbf1e60",
+    "rev": "257fc59a6464f5732a4f49e7dda0fc37475819fb",
     "name": "lake",
     "inputRev?": "master"}},
   {"git":
diff --git a/lean-toolchain b/lean-toolchain
index 3c7418e..03ae79e 100644
--- a/lean-toolchain
+++ b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:nightly-2023-04-11
+leanprover/lean4:nightly-2023-04-20