diff --git a/MachO/Target.h b/MachO/Target.h
index ca71105..ac9c556 100644
--- a/MachO/Target.h
+++ b/MachO/Target.h
@@ -71,10 +71,10 @@
   uint32_t cpuSubtype;
 
   uint64_t pageZeroSize;
-  uint64_t stubSize;
-  uint64_t stubHelperHeaderSize;
-  uint64_t stubHelperEntrySize;
-  uint64_t wordSize;
+  size_t stubSize;
+  size_t stubHelperHeaderSize;
+  size_t stubHelperEntrySize;
+  size_t wordSize;
 };
 
 TargetInfo *createX86_64TargetInfo();
@@ -90,7 +90,7 @@
   static constexpr uint32_t segmentLCType = llvm::MachO::LC_SEGMENT_64;
 
   static constexpr uint64_t pageZeroSize = 1ull << 32;
-  static constexpr uint64_t wordSize = 8;
+  static constexpr size_t wordSize = 8;
 };
 
 struct ILP32 {
@@ -103,7 +103,7 @@
   static constexpr uint32_t segmentLCType = llvm::MachO::LC_SEGMENT;
 
   static constexpr uint64_t pageZeroSize = 1ull << 12;
-  static constexpr uint64_t wordSize = 4;
+  static constexpr size_t wordSize = 4;
 };
 
 extern TargetInfo *target;