diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9bcc135665d0..d38679ed41e9 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -74,7 +74,7 @@ if(LLD_BUILT_STANDALONE)

   set(LLVM_MAIN_INCLUDE_DIR "${MAIN_INCLUDE_DIR}" CACHE PATH "Path to llvm/include")
   set(LLVM_BINARY_DIR "${LLVM_OBJ_ROOT}" CACHE PATH "Path to LLVM build tree")
-  set(LLVM_MAIN_SRC_DIR "${MAIN_SRC_DIR}" CACHE PATH "Path to LLVM source tree")
+  set(LLVM_MAIN_SRC_DIR "${CMAKE_CURRENT_SOURCE_DIR}/../llvm" CACHE PATH "Path to LLVM source tree")

   find_program(LLVM_TABLEGEN_EXE "llvm-tblgen" ${LLVM_TOOLS_BINARY_DIR}
     NO_DEFAULT_PATH)