diff --git a/src/bootstrap/download-ci-llvm-stamp b/src/bootstrap/download-ci-llvm-stamp
index 94630e40f3c4c..36f9aaa595d0f 100644
--- a/src/bootstrap/download-ci-llvm-stamp
+++ b/src/bootstrap/download-ci-llvm-stamp
@@ -1,4 +1,4 @@
 Change this file to make users of the `download-ci-llvm` configuration download
 a new version of LLVM from CI, even if the LLVM submodule hasn’t changed.
 
-Last change is for: https://github.com/rust-lang/rust/pull/104748
+Last change is for: https://github.com/rust-lang/rust/pull/109373
diff --git a/src/bootstrap/native.rs b/src/bootstrap/native.rs
index dff46b500e3ad..f27db5c91e221 100644
--- a/src/bootstrap/native.rs
+++ b/src/bootstrap/native.rs
@@ -309,6 +309,7 @@ impl Step for Llvm {
         cfg.out_dir(&out_dir)
             .profile(profile)
             .define("LLVM_ENABLE_ASSERTIONS", assertions)
+            .define("LLVM_UNREACHABLE_OPTIMIZE", "OFF")
             .define("LLVM_ENABLE_PLUGINS", plugins)
             .define("LLVM_TARGETS_TO_BUILD", llvm_targets)
             .define("LLVM_EXPERIMENTAL_TARGETS_TO_BUILD", llvm_exp_targets)