--- a/memory/mozalloc/mozalloc.h
+++ b/memory/mozalloc/mozalloc.h
@@ -38,24 +38,16 @@
 #if defined(MOZ_ALWAYS_INLINE_EVEN_DEBUG)
 #  define MOZALLOC_INLINE MOZ_ALWAYS_INLINE_EVEN_DEBUG
 #elif defined(HAVE_FORCEINLINE)
 #  define MOZALLOC_INLINE __forceinline
 #else
 #  define MOZALLOC_INLINE inline
 #endif
 
-/* Workaround build problem with Sun Studio 12 */
-#if defined(__SUNPRO_C) || defined(__SUNPRO_CC)
-#  undef MOZ_MUST_USE
-#  define MOZ_MUST_USE
-#  undef MOZ_ALLOCATOR
-#  define MOZ_ALLOCATOR
-#endif
-
 #if defined(__cplusplus)
 extern "C" {
 #endif /* ifdef __cplusplus */
 
 /*
  * We need to use malloc_impl and free_impl in this file when they are
  * defined, because of how mozglue.dll is linked on Windows, where using
  * malloc/free would end up using the symbols from the MSVCRT instead of