diff --git a/WORKSPACE b/WORKSPACE
index a487a50..c147989 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -26,6 +26,7 @@ http_archive(
     patches = [
         "//:llvm.patch",
         "//:fix_RISCVGenMacroFusion_build.patch",
+        "//:fix_compiler_rt.patch",
     ],
     strip_prefix = "llvm-project-" + LLVM_COMMIT,
     urls = ["https://github.com/llvm/llvm-project/archive/{commit}.tar.gz".format(commit = LLVM_COMMIT)],
diff --git a/fix_compiler_rt.patch b/fix_compiler_rt.patch
new file mode 100644
index 0000000..775a071
--- /dev/null
+++ b/fix_compiler_rt.patch
@@ -0,0 +1,30 @@
+commit 2b7a01e90d9de4ed3a6c1e114361f80acea15b1b
+Author: David Zbarsky <dzbarsky@gmail.com>
+Date:   Fri Oct 4 16:00:55 2024 -0400
+
+    patch
+
+diff --git a/utils/bazel/llvm-project-overlay/compiler-rt/BUILD.bazel b/utils/bazel/llvm-project-overlay/compiler-rt/BUILD.bazel
+index bba18bfd387a..c075d5fb3770 100644
+--- a/utils/bazel/llvm-project-overlay/compiler-rt/BUILD.bazel
++++ b/utils/bazel/llvm-project-overlay/compiler-rt/BUILD.bazel
+@@ -11,14 +11,11 @@ licenses(["notice"])
+ 
+ cc_library(
+     name = "config",
+-    defines = select({
+-        "@platforms//os:linux": [
+-            "COMPILER_RT_HAS_ATOMICS=1",
+-            "COMPILER_RT_HAS_FCNTL_LCK=1",
+-            "COMPILER_RT_HAS_UNAME=1",
+-        ],
+-        # Will raise error unless supported platforms.
+-    }),
++    defines = [
++        "COMPILER_RT_HAS_ATOMICS=1",
++        "COMPILER_RT_HAS_FCNTL_LCK=1",
++        "COMPILER_RT_HAS_UNAME=1",
++    ],
+ )
+ 
+ WIN32_ONLY_FILES = [