--- a/mozglue/linker/Elfxx.h
+++ b/mozglue/linker/Elfxx.h
@@ -14,17 +14,17 @@
 #else
 #include <elf.h>
 #endif
 #include <endian.h>
 
 /**
  * Generic ELF macros for the target system
  */
-#ifdef HAVE_64BIT_OS
+#ifdef __LP64__
 #define Elf_(type) Elf64_ ## type
 #define ELFCLASS ELFCLASS64
 #define ELF_R_TYPE ELF64_R_TYPE
 #define ELF_R_SYM ELF64_R_SYM
 #ifndef ELF_ST_BIND
 #define ELF_ST_BIND ELF64_ST_BIND
 #endif
 #else

--- a/mozglue/linker/Logging.h
+++ b/mozglue/linker/Logging.h
@@ -63,19 +63,17 @@ private:
 
 #define DEBUG_LOG(...)   \
   do {                   \
     if (MOZ_UNLIKELY(Logging::isVerbose())) {  \
       LOG(__VA_ARGS__);  \
     }                    \
   } while(0)
 
-/* HAVE_64BIT_OS is not defined when building host tools, so use
- * __SIZEOF_POINTER__ */
-#if defined(HAVE_64BIT_OS) || __SIZEOF_POINTER__ == 8
+#if defined(__LP64__)
 #  define PRIxAddr "lx"
 #  define PRIxSize "lx"
 #  define PRIdSize "ld"
 #  define PRIuSize "lu"
 #else
 #  define PRIxAddr "x"
 #  define PRIxSize "x"
 #  define PRIdSize "d"