diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
--- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileToAtoms.cpp
@@ -879,11 +879,11 @@
   llvm::dwarf::DwarfFormat Format = llvm::dwarf::DwarfFormat::DWARF32;
   auto infoData = dataExtractorFromSection(normalizedFile, info);
   uint32_t length = infoData.getU32(&offset);
-  if (length == 0xffffffff) {
+  if (length == llvm::dwarf::DW_LENGTH_DWARF64) {
     Format = llvm::dwarf::DwarfFormat::DWARF64;
     infoData.getU64(&offset);
   }
-  else if (length > 0xffffff00)
+  else if (length >= llvm::dwarf::DW_LENGTH_lo_reserved)
     return llvm::make_error<GenericError>("Malformed DWARF in " + path);
 
   uint16_t version = infoData.getU16(&offset);