diff --git a/packages/common/src/IAPIDef.ts b/packages/common/src/IAPIDef.ts
index 6b82df1..c8307e7 100644
--- a/packages/common/src/IAPIDef.ts
+++ b/packages/common/src/IAPIDef.ts
@@ -183,7 +183,7 @@ export interface IAPIDef {
     }
     put: {
       response: IComment,
-      body: IComment,
+      body: INewComment,
       params: {
         commentId: number
       }
diff --git a/packages/server/src/comment/CommentRoutes.test.ts b/packages/server/src/comment/CommentRoutes.test.ts
index 547b65b..a98595f 100644
--- a/packages/server/src/comment/CommentRoutes.test.ts
+++ b/packages/server/src/comment/CommentRoutes.test.ts
@@ -1,5 +1,5 @@
 import * as CommentTestUtils from './CommentTestUtils'
-import {IStory} from '@rondo/common'
+import {IComment, IStory} from '@rondo/common'
 import {createSite} from '../site/SiteTestUtils'
 import {getStory} from '../story/StoryTestUtils'
 import {test} from '../test'
@@ -78,13 +78,33 @@ describe('comment', () => {
   })
 
   describe('PUT /comments/:commentId', () => {
-    it('updates a comment', () => {
 
+    let comment: IComment
+    beforeEach(async () => {
+      comment = await CommentTestUtils.createRootComment(t, {
+        storyId: story.id,
+        message: 'test',
+      })
+    })
+    it('updates a comment', async () => {
+      await t.put('/comments/:commentId', {
+        params: {
+          commentId: comment.id,
+        },
+      })
+      .send({
+        message: 'test2',
+      })
+      .expect(200)
+
+      const c  = await CommentTestUtils.getCommentById(t, comment.id)
+      expect(c.message).toEqual('test2')
+      // TODO save edit history
     })
 
-    it('fails to update a comment if user is not the owner')
+    // it('fails to update a comment if user is not the owner')
 
-    it('updates a comment if user is site moderator') // TODO later
+    // it('updates a comment if user is site moderator') // TODO later
   })
 
   describe('DELETE /comments/:commentId', () => {
diff --git a/packages/server/src/comment/CommentRoutes.ts b/packages/server/src/comment/CommentRoutes.ts
index aa6ae04..a8a5bb4 100644
--- a/packages/server/src/comment/CommentRoutes.ts
+++ b/packages/server/src/comment/CommentRoutes.ts
@@ -53,9 +53,13 @@ export class CommentRoutes extends BaseRoute<IAPIDef> {
     })
 
     t.put('/comments/:commentId', async req => {
-      const comment = req.body
-      comment.id = req.params.commentId
-      return this.commentService.edit(comment, req.user!.id)
+      const commentId = Number(req.params.commentId)
+      const {message} = req.body
+      return this.commentService.edit({
+        id: commentId,
+        message,
+        userId: req.user!.id,
+      })
     })
 
     t.delete('/comments/:commentId', async req => {
diff --git a/packages/server/src/comment/CommentService.ts b/packages/server/src/comment/CommentService.ts
index c4fa5b3..c25101c 100644
--- a/packages/server/src/comment/CommentService.ts
+++ b/packages/server/src/comment/CommentService.ts
@@ -1,6 +1,7 @@
 import {BaseService} from '../services/BaseService'
 import {Comment} from '../entities/Comment'
-import {IComment, ICommentTree} from '@rondo/common'
+import {ICommentTree} from '@rondo/common'
+import {IEditCommentParams} from './IEditCommentParams'
 import {ICommentService} from './ICommentService'
 import {INewCommentParams} from './INewCommentParams'
 import {INewRootCommentParams} from './INewRootCommentParams'
@@ -92,22 +93,26 @@ export class CommentService extends BaseService implements ICommentService {
     })
   }
 
-  async edit(comment: IComment, userId: number) {
+  async edit(comment: IEditCommentParams) {
     new Validator(comment)
     .ensure('id')
     .ensure('message')
+    .ensure('userId')
     .throw()
 
+    const {id, message, userId} = comment
+
     await this.getRepository(Comment)
     .update({
-      id: comment.id,
+      id,
       userId,
     }, {
-      message: comment.message,
+      message,
     })
     const editedComment = await this.findOne(comment.id)
 
     if (!editedComment) {
+      // TODO 400 or 404
       throw new Error('Comment not found')
     }
     return editedComment
diff --git a/packages/server/src/comment/CommentTestUtils.ts b/packages/server/src/comment/CommentTestUtils.ts
index d3d3a55..35ad9c3 100644
--- a/packages/server/src/comment/CommentTestUtils.ts
+++ b/packages/server/src/comment/CommentTestUtils.ts
@@ -52,3 +52,16 @@ export async function getComments(
 
   return response.body!
 }
+
+export async function getCommentById(
+  t: RequestTester<IAPIDef>,
+  commentId: number,
+) {
+  const response = await t
+  .get('/comments/:commentId', {
+    params: {commentId},
+  })
+  .expect(200)
+
+  return response.body!
+}
diff --git a/packages/server/src/comment/ICommentService.ts b/packages/server/src/comment/ICommentService.ts
index 9b87667..03e902e 100644
--- a/packages/server/src/comment/ICommentService.ts
+++ b/packages/server/src/comment/ICommentService.ts
@@ -1,4 +1,5 @@
 import {IComment, ICommentTree} from '@rondo/common'
+import {IEditCommentParams} from './IEditCommentParams'
 import {INewCommentParams} from './INewCommentParams'
 import {INewRootCommentParams} from './INewRootCommentParams'
 
@@ -11,7 +12,7 @@ export interface ICommentService {
 
   save(comment: INewCommentParams): Promise<IComment>
 
-  edit(comment: IComment, userId: number): Promise<IComment>
+  edit(comment: IEditCommentParams): Promise<IComment>
 
   delete(commentId: number, userId: number): Promise<IComment | undefined>
 
diff --git a/packages/server/src/comment/IEditCommentParams.ts b/packages/server/src/comment/IEditCommentParams.ts
new file mode 100644
index 0000000..44675f8
--- /dev/null
+++ b/packages/server/src/comment/IEditCommentParams.ts
@@ -0,0 +1,5 @@
+export interface IEditCommentParams {
+  id: number
+  message: string
+  userId: number
+}