diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -94,8 +94,8 @@
 
         * Running a serial build will be **slow**.  To improve speed, try running a
           parallel build.  That's done by default in Ninja; for ``make``, use the option
-          ``-j NNN``, where ``NNN`` is the number of parallel jobs, e.g. the number of
-          CPUs you have.
+          ``-j NNN``, where ``NNN`` is the number of parallel jobs to run.
+          It is recommended to specify the number of CPU cores you have via ``-j$(nproc)`.
 
       * For more information see [CMake](https://llvm.org/docs/CMake.html)