diff --git a/include/fmt/base.h b/include/fmt/base.h
index a04dd5d9..d6cfbd37 100644
--- a/include/fmt/base.h
+++ b/include/fmt/base.h
@@ -276,15 +276,11 @@
 #  define FMT_OPTIMIZE_SIZE 0
 #endif
 
-// Specifies whether to handle built-in and string types specially.
 // FMT_BUILTIN_TYPE=0 may result in smaller library size at the cost of higher
-// per-call binary size.
+// per-call binary size by passing built-in types through the extension API.
 #ifndef FMT_BUILTIN_TYPES
 #  define FMT_BUILTIN_TYPES 1
 #endif
-#if !FMT_BUILTIN_TYPES && !defined(__cpp_if_constexpr)
-#  error FMT_BUILTIN_TYPES=0 requires constexpr if support
-#endif
 
 #define FMT_APPLY_VARIADIC(expr) \
   using ignore = int[];          \
@@ -2195,7 +2191,7 @@ template <typename Context> class value {
   }
   FMT_CONSTEXPR FMT_INLINE value(const char_type* x FMT_BUILTIN) {
     string.data = x;
-    if (is_constant_evaluated()) string.size = {};
+    if (is_constant_evaluated()) string.size = 0;
   }
   FMT_CONSTEXPR FMT_INLINE value(basic_string_view<char_type> x FMT_BUILTIN) {
     string.data = x.data();
@@ -2238,11 +2234,6 @@ template <typename Context> class value {
 #if defined(__cpp_if_constexpr)
     if constexpr (!formattable) type_is_unformattable_for<T, char_type> _;
 
-    if constexpr (std::is_same<T, int>::value) {
-      int_value = x;  // int is always handled as a built-in type.
-      return;
-    }
-
     // T may overload operator& e.g. std::vector<bool>::reference in libc++.
     if constexpr (std::is_same<decltype(&x), remove_reference_t<T>*>::value)
       custom.value = const_cast<value_type*>(&x);
diff --git a/include/fmt/format.h b/include/fmt/format.h
index ad66aeb2..2a1fb1b9 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -1028,9 +1028,7 @@ FMT_API void print(std::FILE*, string_view);
 FMT_BEGIN_EXPORT
 
 // Suppress a misleading warning in older versions of clang.
-#if FMT_CLANG_VERSION
-#  pragma clang diagnostic ignored "-Wweak-vtables"
-#endif
+FMT_CLANG_PRAGMA(diagnostic ignored "-Wweak-vtables")
 
 /// An error reported from a formatting function.
 class FMT_SO_VISIBILITY("default") format_error : public std::runtime_error {