diff --git a/misc.h b/misc.h
index 54648569..12529781 100644
--- a/misc.h
+++ b/misc.h
@@ -386,21 +386,6 @@ inline PTR PtrSub(PTR pointer, OFF offset)
 	return pointer-static_cast<ptrdiff_t>(offset);
 }
 
-/// \brief Determine pointer difference
-/// \tparam PTR a pointer type
-/// \param pointer1 the first pointer
-/// \param pointer2 the second pointer
-/// \details PtrByteDiff can be used to squash Clang and GCC
-///   UBsan findings for pointer addition and subtraction.
-///   pointer1 and pointer2 must point to the same object or
-///   array (or one past the end), and yields the number of
-///   bytes (not elements) difference.
-template <typename PTR>
-inline uintptr_t PtrByteDiff(const PTR pointer1, const PTR pointer2)
-{
-	return static_cast<uintptr_t>(pointer1) - static_cast<uintptr_t>(pointer2);
-}
-
 /// \brief Determine pointer difference
 /// \tparam PTR a pointer type
 /// \param pointer1 the first pointer
@@ -413,7 +398,22 @@ inline uintptr_t PtrByteDiff(const PTR pointer1, const PTR pointer2)
 template <typename PTR>
 inline ptrdiff_t PtrDiff(const PTR pointer1, const PTR pointer2)
 {
-	return static_cast<ptrdiff_t>(pointer1 - pointer2);
+	return pointer1 - pointer2;
+}
+
+/// \brief Determine pointer difference
+/// \tparam PTR a pointer type
+/// \param pointer1 the first pointer
+/// \param pointer2 the second pointer
+/// \details PtrByteDiff can be used to squash Clang and GCC
+///   UBsan findings for pointer addition and subtraction.
+///   pointer1 and pointer2 must point to the same object or
+///   array (or one past the end), and yields the number of
+///   bytes (not elements) difference.
+template <typename PTR>
+inline size_t PtrByteDiff(const PTR pointer1, const PTR pointer2)
+{
+	return (size_t)(static_cast<uintptr_t>(pointer1) - static_cast<uintptr_t>(pointer2));
 }
 
 #if (!__STDC_WANT_SECURE_LIB__ && !defined(_MEMORY_S_DEFINED)) || defined(CRYPTOPP_WANT_SECURE_LIB)