diff --git a/memory/mozalloc/mozalloc.h b/memory/mozalloc/mozalloc.h
--- a/memory/mozalloc/mozalloc.h
+++ b/memory/mozalloc/mozalloc.h
@@ -170,16 +170,22 @@ MFBT_API void* moz_xvalloc(size_t size)
 #define MOZALLOC_THROW_IF_HAS_EXCEPTIONS throw()
 #define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS
 #elif defined(_MSC_VER)
 /*
  * Suppress build warning spam (bug 578546).
  */
 #define MOZALLOC_THROW_IF_HAS_EXCEPTIONS
 #define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS
+#elif __cplusplus >= 201103
+/*
+ * C++11 has deprecated exception-specifications in favour of |noexcept|.
+ */
+#define MOZALLOC_THROW_IF_HAS_EXCEPTIONS noexcept(true)
+#define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS noexcept(false)
 #else
 #define MOZALLOC_THROW_IF_HAS_EXCEPTIONS throw()
 #define MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS throw(std::bad_alloc)
 #endif
 
 #define MOZALLOC_THROW_BAD_ALLOC MOZALLOC_THROW_BAD_ALLOC_IF_HAS_EXCEPTIONS
 
 MOZALLOC_EXPORT_NEW