diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 426db56..7ea3161 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -665,6 +665,8 @@
     Res.push_back("-pthread");
   if (Opts.Blocks)
     Res.push_back("-fblocks");
+  if (Opts.BlocksRuntimeOptional)
+    Res.push_back("-fblocks-runtime-optional");
   if (Opts.EmitAllDecls)
     Res.push_back("-femit-all-decls");
   if (Opts.MathErrno)
@@ -1667,6 +1669,7 @@
 
   Opts.RTTI = !Args.hasArg(OPT_fno_rtti);
   Opts.Blocks = Args.hasArg(OPT_fblocks);
+  Opts.BlocksRuntimeOptional = Args.hasArg(OPT_fblocks_runtime_optional);
   Opts.CharIsSigned = !Args.hasArg(OPT_fno_signed_char);
   Opts.ShortWChar = Args.hasArg(OPT_fshort_wchar);
   Opts.ShortEnums = Args.hasArg(OPT_fshort_enums);