diff --git a/src/hb-coretext.cc b/src/hb-coretext.cc
index 42ea3ea..6d00151 100644
--- a/src/hb-coretext.cc
+++ b/src/hb-coretext.cc
@@ -171,7 +171,7 @@
   if (CFStringHasPrefix (cg_postscript_name, CFSTR (".SFNSText")) ||
       CFStringHasPrefix (cg_postscript_name, CFSTR (".SFNSDisplay")))
   {
-#if MAC_OS_X_VERSION_MIN_REQUIRED < 1080
+#if TARGET_OS_MAC && !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1080
 # define kCTFontUIFontSystem kCTFontSystemFontType
 # define kCTFontUIFontEmphasizedSystem kCTFontEmphasizedSystemFontType
 #endif
@@ -214,7 +214,7 @@
   }
 
   CFURLRef original_url = nullptr;
-#if TARGET_OS_OSX && MAC_OS_X_VERSION_MIN_REQUIRED < 1060
+#if TARGET_OS_MAC && !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1060
   ATSFontRef atsFont;
   FSRef fsref;
   OSStatus status;
@@ -244,7 +244,7 @@
        * process in Blink. This can be detected by the new file URL location
        * that the newly found font points to. */
       CFURLRef new_url = nullptr;
-#if TARGET_OS_OSX && MAC_OS_X_VERSION_MIN_REQUIRED < 1060
+#if TARGET_OS_MAC && !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1060
       atsFont = CTFontGetPlatformFont (new_ct_font, NULL);
       status = ATSFontGetFileReference (atsFont, &fsref);
       if (status == noErr)
@@ -711,7 +711,7 @@
 /* What's the iOS equivalent of this check?
  * The symbols was introduced in iOS 7.0.
  * At any rate, our fallback is safe and works fine. */
-#if MAC_OS_X_VERSION_MIN_REQUIRED < 1090
+#if TARGET_OS_MAC && !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1090
 #  define kCTLanguageAttributeName CFSTR ("NSLanguage")
 #endif
         CFStringRef lang = CFStringCreateWithCStringNoCopy (kCFAllocatorDefault,
@@ -783,7 +783,7 @@
 
       int level = HB_DIRECTION_IS_FORWARD (buffer->props.direction) ? 0 : 1;
       CFNumberRef level_number = CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &level);
-#if MAC_OS_X_VERSION_MIN_REQUIRED < 1060
+#if TARGET_OS_MAC && !(defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && MAC_OS_X_VERSION_MIN_REQUIRED < 1060
       extern const CFStringRef kCTTypesetterOptionForcedEmbeddingLevel;
 #endif
       CFDictionaryRef options = CFDictionaryCreate (kCFAllocatorDefault,
diff --git a/src/hb-dsalgs.hh b/src/hb-dsalgs.hh
index cb3057c..0da244f 100644
--- a/src/hb-dsalgs.hh
+++ b/src/hb-dsalgs.hh
@@ -299,33 +299,19 @@
 }
 
 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,