diff --git a/backend/src/federation/client/1_0/AuthenticationClient.ts b/backend/src/federation/client/1_0/AuthenticationClient.ts
index 6ee69d00d..c1d921823 100644
--- a/backend/src/federation/client/1_0/AuthenticationClient.ts
+++ b/backend/src/federation/client/1_0/AuthenticationClient.ts
@@ -14,7 +14,7 @@ export class AuthenticationClient {
 
   constructor(dbCom: DbFederatedCommunity) {
     this.dbCom = dbCom
-    this.endpoint = ensureUrlEndsWithSlash(dbCom.endPoint).concat(dbCom.apiVersion)
+    this.endpoint = ensureUrlEndsWithSlash(dbCom.endPoint).concat(dbCom.apiVersion).concat('/')
     this.client = new GraphQLClient(this.endpoint, {
       method: 'POST',
       jsonSerializer: {