diff --git a/format.cc b/format.cc
index ef1237a7..6f02a81d 100644
--- a/format.cc
+++ b/format.cc
@@ -66,26 +66,10 @@ using fmt::internal::Arg;
 #ifndef FMT_THROW
 # if FMT_EXCEPTIONS
 #  define FMT_THROW(x) throw x
+#  define FMT_RETURN_AFTER_THROW(x)
 # else
-#  ifndef NDEBUG
-#   define FMT_THROW(x) assert(false && #x)
-#  elif defined _MSC_VER
-#   define FMT_THROW(x) __assume(0)
-#  elif defined __clang__ || FMT_GCC_VERSION >= 405
-#   define FMT_THROW(x) __builtin_unreachable()
-#  else
-#   define FMT_THROW(x) std::abort()
-#  endif
-# endif
-#endif
-
-#ifndef FMT_NORETURN
-# if defined __GNUC__ || defined __clang__
-#  define FMT_NORETURN __attribute__((__noreturn__))
-# elif defined _MSC_VER
-#  define FMT_NORETURN __declspec(noreturn)
-# else
-#  define FMT_NORETURN
+#  define FMT_THROW(x) assert(false)
+#  define FMT_RETURN_AFTER_THROW(x) return x
 # endif
 #endif
 
@@ -307,9 +291,9 @@ class WidthHandler : public fmt::internal::ArgVisitor<WidthHandler, unsigned> {
  public:
   explicit WidthHandler(fmt::FormatSpec &spec) : spec_(spec) {}
 
-  FMT_NORETURN
   unsigned visit_unhandled_arg() {
     FMT_THROW(fmt::FormatError("width is not integer"));
+    FMT_RETURN_AFTER_THROW(0);
   }
 
   template <typename T>
@@ -329,9 +313,9 @@ class WidthHandler : public fmt::internal::ArgVisitor<WidthHandler, unsigned> {
 class PrecisionHandler :
     public fmt::internal::ArgVisitor<PrecisionHandler, int> {
  public:
-  FMT_NORETURN
   unsigned visit_unhandled_arg() {
     FMT_THROW(fmt::FormatError("precision is not integer"));
+    FMT_RETURN_AFTER_THROW(0);
   }
 
   template <typename T>