Index: llvm/docs/HowToSubmitABug.rst
===================================================================
--- llvm/docs/HowToSubmitABug.rst
+++ llvm/docs/HowToSubmitABug.rst
@@ -84,7 +84,7 @@
 ------------------------------
 
 If you find that a bug crashes in the optimizer, compile your test-case to a
-``.bc`` file by passing "``-emit-llvm -O0 -c -o foo.bc``".
+``.bc`` file by passing "``-emit-llvm -O0 -Xclang -disable-O0-optnone -c -o foo.bc``".
 Then run:
 
 .. code-block:: bash