tools/clang/scripts/update.py

diff --git a/tools/clang/scripts/update.py b/tools/clang/scripts/update.py
index 8e35b70..76bdbec 100755
--- a/tools/clang/scripts/update.py
+++ b/tools/clang/scripts/update.py
@@ -36,11 +36,11 @@
 # https://chromium.googlesource.com/chromium/src/+/main/docs/updating_clang.md
 # Reverting problematic clang rolls is safe, though.
 # This is the output of `git describe` and is usable as a commit-ish.
-CLANG_REVISION = 'llvmorg-20-init-17108-g29ed6000'
+CLANG_REVISION = 'llvmorg-21-init-853-gba476d0b'
 CLANG_SUB_REVISION = 1
 
 PACKAGE_VERSION = '%s-%s' % (CLANG_REVISION, CLANG_SUB_REVISION)
-RELEASE_VERSION = '20'
+RELEASE_VERSION = '21'
 
 CDS_URL = os.environ.get('CDS_CLANG_BUCKET_OVERRIDE',
     'https://commondatastorage.googleapis.com/chromium-browser-clang')