diff --git a/lib/roman_numerals.dart b/lib/roman_numerals.dart
index 0697888..f2bb0d8 100644
--- a/lib/roman_numerals.dart
+++ b/lib/roman_numerals.dart
@@ -1,5 +1,7 @@
 String integerToRoman(int number) {
   const conversionRules = [
+    (100, 'C'),
+    (90, 'XC'),
     (50, 'L'),
     (40, 'XL'),
     (10, 'X'),