diff --git a/third_party/llvm-10.0/configs/darwin/include/llvm/Config/config.h b/third_party/llvm-10.0/configs/darwin/include/llvm/Config/config.h
index c4f0ea2..22aa5a2 100644
--- a/third_party/llvm-10.0/configs/darwin/include/llvm/Config/config.h
+++ b/third_party/llvm-10.0/configs/darwin/include/llvm/Config/config.h
@@ -74,7 +74,7 @@
 /* #undef HAVE_FFI_H */
 
 /* Define to 1 if you have the `futimens' function. */
-#define HAVE_FUTIMENS 1
+/* #undef HAVE_FUTIMENS */
 
 /* Define to 1 if you have the `futimes' function. */
 #define HAVE_FUTIMES 1
diff --git a/third_party/llvm-10.0/scripts/update.py b/third_party/llvm-10.0/scripts/update.py
index a4c2ab1..d25eecf 100644
--- a/third_party/llvm-10.0/scripts/update.py
+++ b/third_party/llvm-10.0/scripts/update.py
@@ -118,6 +118,8 @@
     '-DLLVM_TEMPORARILY_ALLOW_OLD_TOOLCHAIN=ON'
 ]
 
+# Used when building LLVM for darwin. Affects values set in the generated config files.
+MIN_MACOS_VERSION = '10.10'
 
 @contextlib.contextmanager
 def pushd(new_dir):
@@ -210,6 +212,9 @@
     cmake_options = LLVM_CMAKE_OPTIONS + ['-DLLVM_TARGETS_TO_BUILD=' +
                                           ';'.join(t for t in get_cmake_targets_to_build(name))]
 
+    if name == 'darwin':
+        cmake_options.append('-DCMAKE_OSX_DEPLOYMENT_TARGET={}'.format(MIN_MACOS_VERSION))
+
     os.makedirs(LLVM_OBJS, exist_ok=True)
     run_subprocess(['cmake', host, LLVM_DIR] +
                    cmake_options, log_level=2, cwd=LLVM_OBJS)