diff --git a/llvm/cmake/config-ix.cmake b/llvm/cmake/config-ix.cmake
index 64878d28d9e1e..53cde952416c6 100644
--- a/llvm/cmake/config-ix.cmake
+++ b/llvm/cmake/config-ix.cmake
@@ -124,7 +124,7 @@ if( NOT PURE_WINDOWS )
     endif()
   endif()
   check_library_exists(dl dlopen "" HAVE_LIBDL)
-  check_library_exists(rt clock_gettime "" HAVE_LIBRT)
+  check_library_exists(rt shm_open "" HAVE_LIBRT)
 endif()
 
 # Check for libpfm.