diff --git a/include/fmt/chrono.h b/include/fmt/chrono.h
index 8c5990171083..424ba08c3420 100644
--- a/include/fmt/chrono.h
+++ b/include/fmt/chrono.h
@@ -1161,23 +1161,37 @@ void write_fractional_seconds(OutputIt& out, Duration d, int precision = -1) {
       const int old_num_digits = detail::count_digits(n);
       auto roundingDigit = n % 10;
       n /= 10;
-      if (roundingDigit > 5 || (roundingDigit == 5 && n % 10 % 2 != 0)) {
-        n += 1;
-      } 
-      if (old_num_digits == detail::count_digits(n)) {
-        if (leading_zeroes) {
-          out = std::fill_n(out, leading_zeroes-1, '0');
-          *out++ = '1';
-          out = std::fill_n(out, remaining, '0');
+      if (n) {
+        if (roundingDigit > 5 || (roundingDigit == 5 && n % 10 % 2 != 0)) {
+          n += 1;
+        } 
+        if (old_num_digits == detail::count_digits(n)) {
+          if (leading_zeroes) {
+            out = std::fill_n(out, leading_zeroes-1, '0');
+            *out++ = '1';
+            out = std::fill_n(out, remaining, '0');
+          }
+          else {
+            n -= 1;
+            out = format_decimal<Char>(out, n, remaining).end;
+          }
         }
         else {
-          n -= 1;
+          out = std::fill_n(out, leading_zeroes, '0');
           out = format_decimal<Char>(out, n, remaining).end;
         }
       }
-      else {
-        out = std::fill_n(out, leading_zeroes, '0');
-        out = format_decimal<Char>(out, n, remaining).end;
+      else { 
+        if (roundingDigit >= 5) { 
+          if (leading_zeroes) {
+            out = std::fill_n(out, leading_zeroes-1, '0');
+            *out++ = '1';
+            out = std::fill_n(out, remaining, '0');
+          }
+        }
+        else {
+          out = std::fill_n(out, leading_zeroes, '0');
+        }
       }
       return;
     }
diff --git a/test/chrono-test.cc b/test/chrono-test.cc
index ad45933853ea..189ba49779ee 100644
--- a/test/chrono-test.cc
+++ b/test/chrono-test.cc
@@ -803,6 +803,10 @@ TEST(chrono_test, cpp20_duration_subsecond_support) {
             "12.1");
   EXPECT_EQ(fmt::format("{:.2%S}", std::chrono::milliseconds{99999}),
             "39.99");
+  EXPECT_EQ(fmt::format("{:.2%S}", std::chrono::milliseconds{1000}),
+            "01.00");
+  EXPECT_EQ(fmt::format("{:.3%S}", std::chrono::milliseconds{1}),
+            "00.001");
   EXPECT_EQ(fmt::format("{:.3%S}", std::chrono::seconds{1234}), "34.000");
   EXPECT_EQ(fmt::format("{:.3%S}", std::chrono::hours{1234}), "00.000");
   EXPECT_EQ(fmt::format("{:.5%S}", dms(1.234)), "00.00123");