diff --git a/lake-manifest.json b/lake-manifest.json
index 26301a3..bab0126 100644
--- a/lake-manifest.json
+++ b/lake-manifest.json
@@ -28,6 +28,6 @@
   {"git":
    {"url": "https://github.com/fgdorais/lean4-unicode-basic",
     "subDir?": null,
-    "rev": "4653d015b3ebd3d7980886a4daa75722d1d4e518",
+    "rev": "8851eecfe12ec9afa4fb8fcf55eea994ec12423d",
     "name": "UnicodeBasic",
     "inputRev?": "main"}}]}
diff --git a/lean-toolchain b/lean-toolchain
index 2526786..dfc7b2c 100644
--- a/lean-toolchain
+++ b/lean-toolchain
@@ -1 +1 @@
-leanprover/lean4:nightly-2023-03-07
+leanprover/lean4:nightly-2023-03-15