diff --git a/include/clang/Basic/LangOptions.def b/include/clang/Basic/LangOptions.def
index 8e90bf2..fc78e92 100644
--- a/include/clang/Basic/LangOptions.def
+++ b/include/clang/Basic/LangOptions.def
@@ -53,6 +53,8 @@
 LANGOPT(ObjC2             , 1, 0, "Objective-C 2")
 BENIGN_LANGOPT(ObjCDefaultSynthProperties , 1, 0, 
                "Objective-C auto-synthesized properties")
+BENIGN_LANGOPT(EncodeExtendedBlockSig , 1, 0, 
+               "Encoding extended block type signature")
 BENIGN_LANGOPT(ObjCInferRelatedResultType , 1, 1, 
                "Objective-C related result type inference")
 LANGOPT(Trigraphs         , 1, 0,"trigraphs")
@@ -104,7 +106,6 @@
 LANGOPT(FiniteMathOnly    , 1, 0, "__FINITE_MATH_ONLY__ predefined macro")
 
 BENIGN_LANGOPT(ObjCGCBitmapPrint , 1, 0, "printing of GC's bitmap layout for __weak/__strong ivars")
-BENIGN_LANGOPT(ObjCExtendedBlockEncode , 1, 1, "Do extended encoding of block type signature")
 
 BENIGN_LANGOPT(AccessControl     , 1, 1, "C++ access control")
 LANGOPT(CharIsSigned      , 1, 1, "signed char")
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">,
diff --git a/include/clang/Driver/Options.td b/include/clang/Driver/Options.td
index 7d437a6..77ba17a 100644
--- a/include/clang/Driver/Options.td
+++ b/include/clang/Driver/Options.td
@@ -929,8 +929,6 @@
   HelpText<"Print the full library path of <file>">, MetaVarName<"<file>">;
 def print_ivar_layout : Flag<["-"], "print-ivar-layout">, Flags<[CC1Option]>,
   HelpText<"Enable Objective-C Ivar layout bitmap print trace">;
-def encode_extended_block_sig : Flag<["-"], "encode-extended-block-signature">, Flags<[CC1Option]>,
-  HelpText<"Enable encoding of the extended block type signature">;
 def print_libgcc_file_name : Flag<["-", "--"], "print-libgcc-file-name">,
   HelpText<"Print the library path for \"libgcc.a\"">;
 def print_multi_directory : Flag<["-", "--"], "print-multi-directory">;
diff --git a/include/clang/Driver/ToolChain.h b/include/clang/Driver/ToolChain.h
index 71736d6..89f2697 100644
--- a/include/clang/Driver/ToolChain.h
+++ b/include/clang/Driver/ToolChain.h
@@ -148,6 +148,10 @@
   /// IsObjCDefaultSynthPropertiesDefault - Does this tool chain enable
   /// -fobjc-default-synthesize-properties by default.
   virtual bool IsObjCDefaultSynthPropertiesDefault() const { return false; }
+  
+  /// IsEncodeExtendedBlockSignatureDefault - Does this tool chain enable
+  /// -fencode-extended-block-signature by default.
+  virtual bool IsEncodeExtendedBlockSignatureDefault() const { return false; }
 
   /// IsObjCNonFragileABIDefault - Does this tool chain set
   /// -fobjc-nonfragile-abi by default.
diff --git a/lib/AST/ASTContext.cpp b/lib/AST/ASTContext.cpp
index c192d28..5a92250 100644
--- a/lib/AST/ASTContext.cpp
+++ b/lib/AST/ASTContext.cpp
@@ -4511,7 +4511,7 @@
   QualType BlockTy =
       Expr->getType()->getAs<BlockPointerType>()->getPointeeType();
   // Encode result type.
-  if (getLangOpts().ObjCExtendedBlockEncode)
+  if (getLangOpts().EncodeExtendedBlockSig)
     getObjCEncodingForMethodParameter(Decl::OBJC_TQ_None,
                             BlockTy->getAs<FunctionType>()->getResultType(),
                             S, true /*Extended*/);
@@ -4552,7 +4552,7 @@
         PType = PVDecl->getType();
     } else if (PType->isFunctionType())
       PType = PVDecl->getType();
-    if (getLangOpts().ObjCExtendedBlockEncode)
+    if (getLangOpts().EncodeExtendedBlockSig)
       getObjCEncodingForMethodParameter(Decl::OBJC_TQ_None, PType,
                                       S, true /*Extended*/);
     else
diff --git a/lib/Driver/ToolChains.h b/lib/Driver/ToolChains.h
index 8ea466a..2005d96 100644
--- a/lib/Driver/ToolChains.h
+++ b/lib/Driver/ToolChains.h
@@ -318,6 +318,10 @@
     return true;
   }
 
+  virtual bool IsEncodeExtendedBlockSignatureDefault() const {
+    return true;
+  }
+  
   virtual bool IsObjCNonFragileABIDefault() const {
     // Non-fragile ABI is default for everything but i386.
     return getTriple().getArch() != llvm::Triple::x86;
diff --git a/lib/Driver/Tools.cpp b/lib/Driver/Tools.cpp
index b1e450d..4dea717 100644
--- a/lib/Driver/Tools.cpp
+++ b/lib/Driver/Tools.cpp
@@ -2727,6 +2727,11 @@
     CmdArgs.push_back("-fobjc-default-synthesize-properties");
   }
 
+  // -fencode-extended-block-signature=1 is default.
+  if (getToolChain().IsEncodeExtendedBlockSignatureDefault()) {
+    CmdArgs.push_back("-fencode-extended-block-signature");
+  }
+  
   // Allow -fno-objc-arr to trump -fobjc-arr/-fobjc-arc.
   // NOTE: This logic is duplicated in ToolChains.cpp.
   bool ARC = isObjCAutoRefCount(Args);
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index df4c883..2e8ae63 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -1126,8 +1126,6 @@
 
   if (Args.hasArg(OPT_print_ivar_layout))
     Opts.ObjCGCBitmapPrint = 1;
-  if (Args.hasArg(OPT_encode_extended_block_sig))
-    Opts.ObjCExtendedBlockEncode = 1;
   if (Args.hasArg(OPT_fno_constant_cfstrings))
     Opts.NoConstantCFStrings = 1;
 
@@ -1216,6 +1214,8 @@
     Args.getLastArgValue(OPT_fconstant_string_class);
   Opts.ObjCDefaultSynthProperties =
     Args.hasArg(OPT_fobjc_default_synthesize_properties);
+  Opts.EncodeExtendedBlockSig =
+    Args.hasArg(OPT_fencode_extended_block_signature);
   Opts.EmitAllDecls = Args.hasArg(OPT_femit_all_decls);
   Opts.PackStruct = Args.getLastArgIntValue(OPT_fpack_struct_EQ, 0, Diags);
   Opts.PICLevel = Args.getLastArgIntValue(OPT_pic_level, 0, Diags);
diff --git a/test/CodeGenObjC/extended-block-signature-encode.m b/test/CodeGenObjC/extended-block-signature-encode.m
index 0db41ed..a380856 100644
--- a/test/CodeGenObjC/extended-block-signature-encode.m
+++ b/test/CodeGenObjC/extended-block-signature-encode.m
@@ -1,5 +1,5 @@
-// RUN: %clang_cc1 -fblocks -triple x86_64-apple-darwin -encode-extended-block-signature -emit-llvm %s -o - | FileCheck %s
-// RUN: %clang_cc1 -fblocks -triple x86_64-apple-darwin -emit-llvm %s -o - | FileCheck %s -check-prefix=EXPANDED
+// RUN: %clang_cc1 -fblocks -triple x86_64-apple-darwin -fencode-extended-block-signature -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -fblocks -triple x86_64-apple-darwin -emit-llvm %s -o - | FileCheck %s -check-prefix=BRIEF
 // rdar://12109031
 
 @class NSString, NSArray;
@@ -12,4 +12,4 @@
   ^(BBB arg1, double arg2){ return b1; }(0, 3.14);
 }
 // CHECK: @{{.*}} = private unnamed_addr constant [64 x i8] c"@?<@\22NSString\22@?@\22NSArray\22>24@?0@?<@\22NSString\22@?@\22NSArray\22>8d16\00"
-// CHECK-EXPANDED: @{{.*}} = private unnamed_addr constant [64 x i8] c"@?<@\22NSString\22@?@\22NSArray\22>24@?0@?<@\22NSString\22@?@\22NSArray\22>8d16\00"
+// CHECK-BRIEF: @{{.*}} = private unnamed_addr constant [14 x i8] c"@?24@?0@?8d16\00"
diff --git a/test/Driver/rewrite-legacy-objc.m b/test/Driver/rewrite-legacy-objc.m
index a76175f..2e3f421 100644
--- a/test/Driver/rewrite-legacy-objc.m
+++ b/test/Driver/rewrite-legacy-objc.m
@@ -3,5 +3,5 @@
 // TEST0: clang{{.*}}" "-cc1"
 // TEST0: "-rewrite-objc"
 // FIXME: CHECK-NOT is broken somehow, it doesn't work here. Check adjacency instead.
-// TEST0: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fobjc-default-synthesize-properties" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fdiagnostics-show-option"
+// TEST0: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx-fragile" "-fobjc-default-synthesize-properties" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fdiagnostics-show-option"
 // TEST0: rewrite-legacy-objc.m"
diff --git a/test/Driver/rewrite-objc.m b/test/Driver/rewrite-objc.m
index ca578cf..fa159a6 100644
--- a/test/Driver/rewrite-objc.m
+++ b/test/Driver/rewrite-objc.m
@@ -3,4 +3,4 @@
 // TEST0: clang{{.*}}" "-cc1"
 // TEST0: "-rewrite-objc"
 // FIXME: CHECK-NOT is broken somehow, it doesn't work here. Check adjacency instead.
-// TEST0: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx" "-fobjc-dispatch-method=mixed" "-fobjc-default-synthesize-properties" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fdiagnostics-show-option"
+// TEST0: "-fmessage-length" "0" "-stack-protector" "1" "-mstackrealign" "-fblocks" "-fobjc-runtime=macosx" "-fobjc-dispatch-method=mixed" "-fobjc-default-synthesize-properties" "-fencode-extended-block-signature" "-fno-objc-infer-related-result-type" "-fobjc-exceptions" "-fexceptions" "-fdiagnostics-show-option"