diff --git a/include/clang/Driver/CC1Options.td b/include/clang/Driver/CC1Options.td
index be0653c..5761d2e 100644
--- a/include/clang/Driver/CC1Options.td
+++ b/include/clang/Driver/CC1Options.td
@@ -406,6 +406,8 @@
   HelpText<"Objective-C dispatch method to use">;
 def fobjc_default_synthesize_properties : Flag<["-"], "fobjc-default-synthesize-properties">,
   HelpText<"enable the default synthesis of Objective-C properties">;
+def fencode_extended_block_signature : Flag<["-"], "fencode-extended-block-signature">,
+  HelpText<"enable extended encoding of block type signature">;
 def pic_level : Separate<["-"], "pic-level">,
   HelpText<"Value for __PIC__">;
 def pie_level : Separate<["-"], "pie-level">,