diff --git a/llvm/lib/ObjCopy/MachO/MachOWriter.cpp b/llvm/lib/ObjCopy/MachO/MachOWriter.cpp
--- a/llvm/lib/ObjCopy/MachO/MachOWriter.cpp
+++ b/llvm/lib/ObjCopy/MachO/MachOWriter.cpp
@@ -651,7 +651,6 @@
     return createStringError(errc::not_enough_memory,
                              "failed to allocate memory buffer of " +
                                  Twine::utohexstr(TotalSize) + " bytes");
-  memset(Buf->getBufferStart(), 0, totalSize());
   writeHeader();
   writeLoadCommands();
   writeSections();