diff --git a/backend/src/interfaces/answer.ts b/backend/src/interfaces/answer.ts
index 493fd3c0..b62aa741 100644
--- a/backend/src/interfaces/answer.ts
+++ b/backend/src/interfaces/answer.ts
@@ -1,14 +1,7 @@
-import { mapToUserDTO, UserDTO } from './user.js';
-import { mapToQuestionDTO, mapToQuestionId, QuestionDTO, QuestionId } from './question.js';
+import { mapToUserDTO } from './user.js';
+import { mapToQuestionDTO, mapToQuestionId } from './question.js';
 import { Answer } from '../entities/questions/answer.entity.js';
-
-export interface AnswerDTO {
-    author: UserDTO;
-    toQuestion: QuestionDTO;
-    sequenceNumber: number;
-    timestamp: string;
-    content: string;
-}
+import { AnswerDTO, AnswerId } from 'dwengo-1-common/src/interfaces/answer';
 
 /**
  * Convert a Question entity to a DTO format.
@@ -23,12 +16,6 @@ export function mapToAnswerDTO(answer: Answer): AnswerDTO {
     };
 }
 
-export interface AnswerId {
-    author: string;
-    toQuestion: QuestionId;
-    sequenceNumber: number;
-}
-
 export function mapToAnswerId(answer: AnswerDTO): AnswerId {
     return {
         author: answer.author.username,
diff --git a/common/src/interfaces/answer.d.ts b/common/src/interfaces/answer.d.ts
new file mode 100644
index 00000000..96ed063b
--- /dev/null
+++ b/common/src/interfaces/answer.d.ts
@@ -0,0 +1,16 @@
+import { UserDTO } from 'dwengo-1-backend/src/interfaces/user.js'
+import { QuestionDTO } from 'dwengo-1-backend/src/interfaces/question.js'
+
+export interface AnswerDTO {
+    author: UserDTO;
+    toQuestion: QuestionDTO;
+    sequenceNumber: number;
+    timestamp: string;
+    content: string;
+}
+
+export interface AnswerId {
+    author: string;
+    toQuestion: QuestionId;
+    sequenceNumber: number;
+}