diff --git a/runtimes/CMakeLists.txt b/runtimes/CMakeLists.txt
--- a/runtimes/CMakeLists.txt
+++ b/runtimes/CMakeLists.txt
@@ -81,10 +81,6 @@
 # This variable is used by individual runtimes to locate LLVM files.
 set(LLVM_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../llvm)
 
-if(APPLE)
-  set(LLVM_ENABLE_LIBCXX ON CACHE BOOL "")
-endif()
-
 include(CheckLibraryExists)
 include(CheckCCompilerFlag)
 include(CheckCXXCompilerFlag)