diff --git a/packages/utils/saferKorean.ts b/packages/utils/saferKorean.ts
index 903fbc1..e85f943 100644
--- a/packages/utils/saferKorean.ts
+++ b/packages/utils/saferKorean.ts
@@ -204,12 +204,12 @@ export function saferKorean(input: string): string {
         .replace(/[ㄱ-ㅎㄲㄸㅃㅆㅉ]/g, (char: string) => ChoseongMap[char as keyof typeof ChoseongMap])
 
         // Process number, unit
-        .replace(/(\+\d+[\s\-]+)?([\d\-]+)/g, (_, prefix: string, phone: string) => {
+        .replace(/(\+\d+[\s\-]+)?([\d\-]+)/g, (_, prefix: string | undefined, phone: string) => {
             const all = (prefix ?? "") + phone;
             if (!phone.includes("-")) return all;
             return PhoneNumberKorean.convert(all);
         })
-        .replace(/([\d,]+)([kKMmgGtTpP][iI]?)[bB]/g, (_, num: string, mod: string) => {
+        .replace(/([\d,]+)([kKMmgGtTpPeEzZyY][iI]?)[bB]/g, (_, num: string, mod: string) => {
             // 10kib => 십키비바이트
             num = IntegerKorean.convertFromString(num);
             mod = SIPrefix[mod.toLowerCase() as keyof typeof SIPrefix];