Index: lib/Rewrite/RewriteObjC.cpp
===================================================================
--- lib/Rewrite/RewriteObjC.cpp	(revision 162401)
+++ lib/Rewrite/RewriteObjC.cpp	(working copy)
@@ -5119,8 +5119,8 @@
   Preamble += "__OBJC_RW_DLLIMPORT int objc_exception_match";
   Preamble += "(struct objc_class *, struct objc_object *);\n";
   // @synchronized hooks.
-  Preamble += "__OBJC_RW_DLLIMPORT void objc_sync_enter(struct objc_object *);\n";
-  Preamble += "__OBJC_RW_DLLIMPORT void objc_sync_exit(struct objc_object *);\n";
+  Preamble += "__OBJC_RW_DLLIMPORT int objc_sync_enter(struct objc_object *);\n";
+  Preamble += "__OBJC_RW_DLLIMPORT int objc_sync_exit(struct objc_object *);\n";
   Preamble += "__OBJC_RW_DLLIMPORT Protocol *objc_getProtocol(const char *);\n";
   Preamble += "#ifndef __FASTENUMERATIONSTATE\n";
   Preamble += "struct __objcFastEnumerationState {\n\t";
Index: lib/Rewrite/RewriteModernObjC.cpp
===================================================================
--- lib/Rewrite/RewriteModernObjC.cpp	(revision 162401)
+++ lib/Rewrite/RewriteModernObjC.cpp	(working copy)
@@ -5901,8 +5901,8 @@
   Preamble += "(const char *);\n";
   Preamble += "__OBJC_RW_DLLIMPORT void objc_exception_throw( struct objc_object *);\n";
   // @synchronized hooks.
-  Preamble += "__OBJC_RW_DLLIMPORT void objc_sync_enter( struct objc_object *);\n";
-  Preamble += "__OBJC_RW_DLLIMPORT void objc_sync_exit( struct objc_object *);\n";
+  Preamble += "__OBJC_RW_DLLIMPORT int objc_sync_enter( struct objc_object *);\n";
+  Preamble += "__OBJC_RW_DLLIMPORT int objc_sync_exit( struct objc_object *);\n";
   Preamble += "__OBJC_RW_DLLIMPORT Protocol *objc_getProtocol(const char *);\n";
   Preamble += "#ifndef __FASTENUMERATIONSTATE\n";
   Preamble += "struct __objcFastEnumerationState {\n\t";