we use different LLVM/Clang includes layout
---
--- a/cl_headers/CMakeLists.txt
+++ b/cl_headers/CMakeLists.txt
@@ -13,7 +13,7 @@
 
 if(USE_PREBUILT_LLVM)
     set(OPENCL_HEADERS_DIR
-      "${LLVM_LIBRARY_DIRS}/clang/${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}/include/")
+      "/usr/lib/clang/${LLVM_VERSION_MAJOR}.${LLVM_VERSION_MINOR}.${LLVM_VERSION_PATCH}/include/")
 else(USE_PREBUILT_LLVM)
     set(OPENCL_HEADERS_DIR "${CLANG_SOURCE_DIR}/lib/Headers")
 endif(USE_PREBUILT_LLVM)