src/main/java/de/szut/lf8_starter/welcome/WelcomeController.java

@@ -19,7 +19,7 @@ public class WelcomeController {
     }
 
     @GetMapping("/roles")
-    public ResponseEntity<Collection<? extends GrantedAuthority>> getRoles(Authentication authentication) {
+    public ResponseEntity getRoles(Authentication authentication) {
         return ResponseEntity.ok(authentication.getAuthorities());
     }