diff --git a/server/lib/database/channel.ts b/server/lib/database/channel.ts
index fdbcfee2..f71fa2b7 100644
--- a/server/lib/database/channel.ts
+++ b/server/lib/database/channel.ts
@@ -18,9 +18,34 @@ async function getChannelNameById (options: RegisterServerOptions, channelId: nu
     options.peertubeHelpers.logger.debug(`getChannelNameById: channel ${channelId} not found.`)
     return null
   }
-  return (results[0].preferredUsername ?? null) as string
+  return results[0].preferredUsername ?? null
+}
+
+async function getUserNameByChannelId (options: RegisterServerOptions, channelId: number): Promise<string | null> {
+  if (!channelId) {
+    throw new Error('Missing channelId')
+  }
+  if (!Number.isInteger(channelId)) {
+    throw new Error('Invalid channelId: not an integer')
+  }
+  const [results] = await options.peertubeHelpers.database.query(
+    'SELECT "user"."username"' +
+    ' FROM "videoChannel"' +
+    ' JOIN "account" ON "account"."id" = "videoChannel"."accountId"' +
+    ' JOIN "user" ON "account"."userId" = "user"."id" ' +
+    ' WHERE "videoChannel"."id" = ' + channelId.toString()
+  )
+  if (!Array.isArray(results)) {
+    throw new Error('getUserNameByChannelId: query result is not an array.')
+  }
+  if (!results[0]) {
+    options.peertubeHelpers.logger.debug(`getUserNameByChannelId: channel ${channelId} not found.`)
+    return null
+  }
+  return results[0].username ?? null
 }
 
 export {
-  getChannelNameById
+  getChannelNameById,
+  getUserNameByChannelId
 }
diff --git a/server/lib/prosody/config/affiliations.ts b/server/lib/prosody/config/affiliations.ts
index 47dea2d1..04c274ef 100644
--- a/server/lib/prosody/config/affiliations.ts
+++ b/server/lib/prosody/config/affiliations.ts
@@ -1,4 +1,5 @@
 import { getProsodyDomain } from './domain'
+import { getUserNameByChannelId } from '../../database/channel'
 
 interface Affiliations { [jid: string]: 'outcast' | 'none' | 'member' | 'admin' | 'owner' }
 
@@ -45,30 +46,11 @@ async function getVideoAffiliations (options: RegisterServerOptions, video: MVid
 }
 
 async function _getVideoOwnerUsername (options: RegisterServerOptions, video: MVideoThumbnail): Promise<string> {
-  // checking type of video.channelId
-  if (!video.channelId) {
-    throw new Error('Missing channelId on video')
+  const username = await getUserNameByChannelId(options, video.channelId)
+  if (username === null) {
+    throw new Error('Username not found')
   }
-  if (!Number.isInteger(video.channelId)) {
-    throw new Error('Invalid channelId: not an integer')
-  }
-  const [results] = await options.peertubeHelpers.database.query(
-    'SELECT "user"."username"' +
-    ' FROM "videoChannel"' +
-    ' JOIN "account" ON "account"."id" = "videoChannel"."accountId"' +
-    ' JOIN "user" ON "account"."userId" = "user"."id" ' +
-    ' WHERE "videoChannel"."id" = ' + video.channelId.toString()
-  )
-  if (!Array.isArray(results)) {
-    throw new Error('_getVideoOwnerUsername: query result is not an array.')
-  }
-  if (!results[0]) {
-    throw new Error('_getVideoOwnerUsername: no user found')
-  }
-  if (!results[0].username) {
-    throw new Error('_getVideoOwnerUsername: no username in result')
-  }
-  return results[0].username as string
+  return username
 }
 
 export {