diff --git a/infra/base-images/base-clang/checkout_build_install_llvm.sh b/infra/base-images/base-clang/checkout_build_install_llvm.sh
index dd9a6cc6f..63d39ca20 100755
--- a/infra/base-images/base-clang/checkout_build_install_llvm.sh
+++ b/infra/base-images/base-clang/checkout_build_install_llvm.sh
@@ -26,8 +26,8 @@ cd $SRC/chromium_tools
 git clone https://chromium.googlesource.com/chromium/src/tools/clang
 cd clang
 
-OUR_LLVM_REVISION=335507  # For manual bumping.
-FORCE_OUR_REVISION=0  # To allow for manual downgrades.
+OUR_LLVM_REVISION=334100  # For manual bumping.
+FORCE_OUR_REVISION=1  # To allow for manual downgrades.
 LLVM_REVISION=$(grep -Po "CLANG_REVISION = '\K\d+(?=')" scripts/update.py)
 
 if [ $OUR_LLVM_REVISION -gt $LLVM_REVISION ] || [ $FORCE_OUR_REVISION -ne 0 ]; then