diff --git a/api/v1/serializers/school.py b/api/v1/serializers/school.py
index caceba24..7bb15b00 100644
--- a/api/v1/serializers/school.py
+++ b/api/v1/serializers/school.py
@@ -76,18 +76,18 @@ class SchoolScheduleSerializer(serializers.ModelSerializer):
         return schoolschedule
 
     def dispatch_gallery(self, schoolschedule, gallery):
+        images = list(SchoolScheduleImage.objects.filter(schoolschedule=schoolschedule).values_list('img', flat=True))
+        new_images = []
         for image in gallery:
-
-            imgs = SchoolScheduleImage.objects.filter(
-                schoolschedule=schoolschedule,
-                img=image['img']
-            )
-
-            if not imgs.exists():
-                si = SchoolScheduleImage.objects.create(
-                    schoolschedule=schoolschedule,
-                    img=image['img'],
-                )
+            if image.get('img'):
+                if image['img'].id not in images:
+                    SchoolScheduleImage.objects.create(
+                        schoolschedule=schoolschedule,
+                        img=image['img'],
+                    )
+                new_images.append(image['img'].id)
+        SchoolScheduleImage.objects.filter(schoolschedule=schoolschedule, img__isnull=True).delete()
+        SchoolScheduleImage.objects.filter(schoolschedule=schoolschedule, img__in=set(images) - set(new_images)).delete()
 
     def to_representation(self, instance):
         return SchoolScheduleSerializerImg(instance, context=self.context).to_representation(instance)