diff --git a/src/hb-dsalgs.hh b/src/hb-dsalgs.hh
index cb3057c54..0da244f0a 100644
--- a/src/hb-dsalgs.hh
+++ b/src/hb-dsalgs.hh
@@ -299,33 +299,19 @@ hb_ceil_to_4 (unsigned int v)
 }
 
 template <typename T> struct hb_is_signed;
-template <> struct hb_is_signed<signed char> { enum { value = true }; };
-template <> struct hb_is_signed<signed short> { enum { value = true }; };
-template <> struct hb_is_signed<signed int> { enum { value = true }; };
-template <> struct hb_is_signed<signed long> { enum { value = true }; };
-template <> struct hb_is_signed<unsigned char> { enum { value = false }; };
-template <> struct hb_is_signed<unsigned short> { enum { value = false }; };
-template <> struct hb_is_signed<unsigned int> { enum { value = false }; };
-template <> struct hb_is_signed<unsigned long> { enum { value = false }; };
-/* We need to define hb_is_signed for the typedefs we use on pre-Visual
- * Studio 2010 for the int8_t type, since __int8/__int64 is not considered
- * the same as char/long.  The previous lines will suffice for the other
- * types, though.  Note that somehow, unsigned __int8 is considered same
- * as unsigned char.
- * https://github.com/harfbuzz/harfbuzz/pull/1499
- */
-#if defined(_MSC_VER) && (_MSC_VER < 1600)
-template <> struct hb_is_signed<__int8> { enum { value = true }; };
-#endif
+/* https://github.com/harfbuzz/harfbuzz/issues/1535 */
+template <> struct hb_is_signed<int8_t> { enum { value = true }; };
+template <> struct hb_is_signed<int16_t> { enum { value = true }; };
+template <> struct hb_is_signed<int32_t> { enum { value = true }; };
+template <> struct hb_is_signed<int64_t> { enum { value = true }; };
+template <> struct hb_is_signed<uint8_t> { enum { value = false }; };
+template <> struct hb_is_signed<uint16_t> { enum { value = false }; };
+template <> struct hb_is_signed<uint32_t> { enum { value = false }; };
+template <> struct hb_is_signed<uint64_t> { enum { value = false }; };
 
 template <typename T> static inline bool
 hb_in_range (T u, T lo, T hi)
 {
-  /* The sizeof() is here to force template instantiation.
-   * I'm sure there are better ways to do this but can't think of
-   * one right now.  Declaring a variable won't work as HB_UNUSED
-   * is unusable on some platforms and unused types are less likely
-   * to generate a warning than unused variables. */
   static_assert (!hb_is_signed<T>::value, "");
 
   /* The casts below are important as if T is smaller than int,