diff --git a/src/hb-meta.hh b/src/hb-meta.hh
index d995607f4..e5eae564d 100644
--- a/src/hb-meta.hh
+++ b/src/hb-meta.hh
@@ -47,9 +47,9 @@ template<typename... Ts> using hb_head_tt = typename _hb_head_tt<Ts...>::type;
 
 /* Bool!  For when we need to evaluate type-dependent expressions
  * in a template argument. */
-template <bool b> struct hb_bool_tt { static constexpr bool value = b; };
-typedef hb_bool_tt<true> hb_true_t;
-typedef hb_bool_tt<false> hb_false_t;
+template <bool b> struct hb_bool_constant { static constexpr bool value = b; };
+typedef hb_bool_constant<true> hb_true_t;
+typedef hb_bool_constant<false> hb_false_t;
 
 
 /* Basic type SFINAE. */
diff --git a/src/hb-null.hh b/src/hb-null.hh
index 562c4abc0..fea881af6 100644
--- a/src/hb-null.hh
+++ b/src/hb-null.hh
@@ -50,7 +50,7 @@ template <typename T, typename B>
 struct _hb_null_size
 { enum { value = sizeof (T) }; };
 template <typename T>
-struct _hb_null_size<T, hb_bool_tt<true || sizeof (T::min_size)>>
+struct _hb_null_size<T, hb_bool_constant<true || sizeof (T::min_size)>>
 { enum { value = T::null_size }; };
 
 template <typename T>
@@ -67,7 +67,7 @@ template <typename T, typename B>
 struct _hb_static_size
 { enum { value = sizeof (T) }; };
 template <typename T>
-struct _hb_static_size<T, hb_bool_tt<true || sizeof (T::min_size)>>
+struct _hb_static_size<T, hb_bool_constant<true || sizeof (T::min_size)>>
 { enum { value = T::static_size }; };
 
 template <typename T>