diff --git a/include/fmt/format.h b/include/fmt/format.h
index 95604051c0ee..6e80001fce26 100644
--- a/include/fmt/format.h
+++ b/include/fmt/format.h
@@ -1998,7 +1998,10 @@ auto write_int_localized(OutputIt out, UInt value, unsigned prefix,
                               grouping.count_separators(num_digits));
   return write_padded<align::right>(
       out, specs, size, size, [&](reserve_iterator<OutputIt> it) {
-        if (prefix != 0) *it++ = static_cast<Char>(prefix);
+        if (prefix != 0) {
+          char sign = static_cast<char>(prefix);
+          *it++ = static_cast<Char>(sign);
+        }
         return grouping.apply(it, string_view(digits, to_unsigned(num_digits)));
       });
 }
@@ -2157,7 +2160,8 @@ class counting_iterator {
     return it;
   }
 
-  FMT_CONSTEXPR friend counting_iterator operator+(counting_iterator it, difference_type n) {
+  FMT_CONSTEXPR friend counting_iterator operator+(counting_iterator it,
+                                                   difference_type n) {
     it.count_ += static_cast<size_t>(n);
     return it;
   }
diff --git a/test/xchar-test.cc b/test/xchar-test.cc
index fce3e977ebc4..b3da1f556db3 100644
--- a/test/xchar-test.cc
+++ b/test/xchar-test.cc
@@ -513,4 +513,8 @@ TEST(locale_test, chrono_weekday) {
   std::locale::global(loc_old);
 }
 
+TEST(locale_test, sign) {
+  EXPECT_EQ(fmt::format(std::locale(), L"{:L}", -50), L"-50");
+}
+
 #endif  // FMT_STATIC_THOUSANDS_SEPARATOR