diff --git a/compiler-rt/CMakeLists.txt b/compiler-rt/CMakeLists.txt
index 4054b8619e070903c3681aef1f007bbf2e5f822d..34af8f222f36f26b244534c3b7a5adc39f16c5f5 100644
--- a/compiler-rt/CMakeLists.txt
+++ b/compiler-rt/CMakeLists.txt
@@ -348,7 +348,7 @@ pythonize_bool(SANITIZER_CAN_USE_CXXABI)
 
 add_subdirectory(include)
 
-find_llvm_external_project(projects libcxx COMPILER_RT_LIBCXX_PATH)
+set(COMPILER_RT_LIBCXX_PATH ${LLVM_MAIN_SRC_DIR}/projects/libcxx)
 if(EXISTS ${COMPILER_RT_LIBCXX_PATH}/)
   set(COMPILER_RT_HAS_LIBCXX_SOURCES TRUE)
 else()