diff --git a/src/main/java/ru/ulstu/activity/common/service/ActivityService.java b/src/main/java/ru/ulstu/activity/common/service/ActivityService.java
index 382965b..1f817b8 100644
--- a/src/main/java/ru/ulstu/activity/common/service/ActivityService.java
+++ b/src/main/java/ru/ulstu/activity/common/service/ActivityService.java
@@ -64,7 +64,7 @@ public abstract class ActivityService<L extends ActivityListDto, T extends Abstr
     public D update(D entityDto) {
         T oldEntity = activityRepository.getById(entityDto.getId());
         //to init lazy collection
-        oldEntity.getActivityMembers();
+        oldEntity.getActivityMembers().size();
         activityRepository.detach(oldEntity);
         T newEntity;
         try {