diff --git a/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java b/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java
index e2aa8b7..85baa1c 100755
--- a/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java
+++ b/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java
@@ -89,7 +89,7 @@ public class ExchangeController extends TokenBasedController {
         final Groups groupInstance = group.get();
 
         if (assignmentInstance.getGroup().getCourseId() != null
-                && assignmentInstance.getGroup().getCourseId().getId() != groupInstance.getCourseId().getId()) {
+                && ! assignmentInstance.getGroup().getCourseId().getId().equals(groupInstance.getCourseId().getId())) {
             return new ResponseEntity<>("You can performe exchange only within one course.", HttpStatus.BAD_REQUEST);
         }