diff --git a/src/pages/overall/overall-course/overall-course.vue b/src/pages/overall/overall-course/overall-course.vue
index c4851b0..582db79 100644
--- a/src/pages/overall/overall-course/overall-course.vue
+++ b/src/pages/overall/overall-course/overall-course.vue
@@ -34,7 +34,8 @@
             <div class="course-card-content expand notification"
                  v-if="countUnread() !== 0">
                 <unread-entry v-for="assignment in unreadAssignments"
-                              :assignment="assignment">
+                              :assignment="assignment"
+                              :key="assignment.id">
                 </unread-entry>
             </div>
         </el-card>
diff --git a/src/pages/overall/overall.vue b/src/pages/overall/overall.vue
index 71bd9c1..b70a829 100644
--- a/src/pages/overall/overall.vue
+++ b/src/pages/overall/overall.vue
@@ -25,7 +25,10 @@
             </el-col>
         </el-row>
 
-        <overall-course v-for="course in courses" :course="course"></overall-course>
+        <overall-course v-for="course in courses"
+                        :course="course"
+                        :key="course.id">
+        </overall-course>
     </div>
 </template>