diff --git a/.changeset/chilly-cameras-lie.md b/.changeset/chilly-cameras-lie.md
new file mode 100644
index 00000000..bd4ce412
--- /dev/null
+++ b/.changeset/chilly-cameras-lie.md
@@ -0,0 +1,5 @@
+---
+"es-hangul": patch
+---
+
+feat: "이라/라" 케이스 추가
diff --git a/src/josa.spec.ts b/src/josa.spec.ts
index 25e33b30..63f23969 100644
--- a/src/josa.spec.ts
+++ b/src/josa.spec.ts
@@ -41,6 +41,10 @@ describe('Hangul', () => {
       expect(josa('고기', '이랑/랑')).toBe('고기랑');
       expect(josa('과일', '이랑/랑')).toBe('과일이랑');
     });
+    it('주제의 보조사', () => {
+      expect(josa('의사', '이라/라')).toBe('의사라');
+      expect(josa('선생님', '이라/라')).toBe('선생님이라');
+    });
     it('서술격조사와 종결어미', () => {
       expect(josa('사과', '이에요/예요')).toBe('사과예요');
       expect(josa('책', '이에요/예요')).toBe('책이에요');
diff --git a/src/josa.ts b/src/josa.ts
index 54abdb6e..6fc5c007 100644
--- a/src/josa.ts
+++ b/src/josa.ts
@@ -14,7 +14,8 @@ type JosaOption =
   | '이에요/예요'
   | '으로서/로서'
   | '으로써/로써'
-  | '으로부터/로부터';
+  | '으로부터/로부터'
+  | '이라/라';
 
 const 로_조사: JosaOption[] = ['으로/로', '으로서/로서', '으로써/로써', '으로부터/로부터'];