diff --git a/CMakeLists.txt b/CMakeLists.txt
index b975c0e..21f851b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -340,5 +340,5 @@ endif()
 set(BUG_REPORT_URL "http://llvm.org/bugs/" CACHE STRING
   "Default URL where bug reports are to be submitted.")
 
-option(CLANG_ORDER_FILE
-  "Order file to use when compiling clang in order to improve startup time." "")
+set(CLANG_ORDER_FILE "" CACHE FILEPATH
+  "Order file to use when compiling clang in order to improve startup time.")