diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -112,7 +112,7 @@
   endif()
 
   # Ensure that fat libraries are built correctly on Darwin
-  if(CMAKE_HOST_APPLE AND APPLE)
+  if(APPLE)
     include(UseLibtool)
   endif()
 
diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -20,7 +20,7 @@
   if(APPLE)
     include(CompilerRTDarwinUtils)
   endif()
-  if(CMAKE_HOST_APPLE AND APPLE)
+  if(APPLE)
     include(UseLibtool)
   endif()
   include(AddCompilerRT)
diff --git a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
--- a/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
+++ b/llvm/cmake/modules/LLVMExternalProjectUtils.cmake
@@ -53,8 +53,10 @@
   endforeach()
 
   if(NOT ARG_TOOLCHAIN_TOOLS)
-    set(ARG_TOOLCHAIN_TOOLS clang lld llvm-ar llvm-lipo llvm-ranlib llvm-nm llvm-objdump)
-    if(NOT _cmake_system_name STREQUAL Darwin)
+    set(ARG_TOOLCHAIN_TOOLS clang lld llvm-ar llvm-ranlib llvm-nm llvm-objdump)
+    if(_cmake_system_name STREQUAL Darwin)
+      list(APPEND ARG_TOOLCHAIN_TOOLS llvm-libtool-darwin llvm-lipo)
+    else()
       # TODO: These tools don't fully support Mach-O format yet.
       list(APPEND ARG_TOOLCHAIN_TOOLS llvm-objcopy llvm-strip)
     endif()
@@ -144,6 +146,9 @@
     if(llvm-ar IN_LIST TOOLCHAIN_TOOLS)
       list(APPEND compiler_args -DCMAKE_AR=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ar${CMAKE_EXECUTABLE_SUFFIX})
     endif()
+    if(llvm-libtool-darwin IN_LIST TOOLCHAIN_TOOLS)
+      list(APPEND compiler_args -DCMAKE_LIBTOOL=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-libtool-darwin${CMAKE_EXECUTABLE_SUFFIX})
+    endif()
     if(llvm-lipo IN_LIST TOOLCHAIN_TOOLS)
       list(APPEND compiler_args -DCMAKE_LIPO=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-lipo${CMAKE_EXECUTABLE_SUFFIX})
     endif()