diff --git a/backend/api/serializers/checks_serializer.py b/backend/api/serializers/checks_serializer.py
index 1ff44824..4713c45d 100644
--- a/backend/api/serializers/checks_serializer.py
+++ b/backend/api/serializers/checks_serializer.py
@@ -3,7 +3,7 @@
 from api.models.project import Project
 from django.utils.translation import gettext as _
 from rest_framework import serializers
-from rest_framework.exceptions import ValidationError
+from rest_framework.exceptions import ValidationError, NotFound
 
 
 class FileExtensionSerializer(serializers.ModelSerializer):
@@ -83,8 +83,7 @@ class Meta:
 
 class ExtraCheckSerializer(serializers.ModelSerializer):
     project = serializers.HyperlinkedIdentityField(
-        view_name="project-detail",
-        read_only=True
+        view_name="project-detail"
     )
 
     docker_image = serializers.HyperlinkedIdentityField(
@@ -95,9 +94,25 @@ class Meta:
         model = ExtraCheck
         fields = "__all__"
 
-    def validate(self, attrs):
+    def validate(self, attrs: dict) -> dict:
+        """Validate the extra check"""
         data = super().validate(attrs)
 
+        # Check if the docker image is provided
+        if not "docker_image" in self.initial_data:
+            raise serializers.ValidationError(_("extra_check.error.docker_image"))
+
+        # Check if the docker image exists
+        image = DockerImage.objects.get(
+            id=self.initial_data["docker_image"]
+        )
+
+        if image is None:
+            raise NotFound(_("extra_check.error.docker_image"))
+
+        data["docker_image"] = image
+
+        # Check if the time limit and memory limit are in the correct range
         if "time_limit" in data and not 10 <= data["time_limit"] <= 1000:
             raise serializers.ValidationError(_("extra_check.error.time_limit"))
 
diff --git a/backend/api/views/project_view.py b/backend/api/views/project_view.py
index 4d01e5e4..dc2243d9 100644
--- a/backend/api/views/project_view.py
+++ b/backend/api/views/project_view.py
@@ -1,8 +1,3 @@
-import logging
-
-from rest_framework.exceptions import ValidationError
-from rest_framework.parsers import MultiPartParser
-
 from api.models.group import Group
 from api.models.project import Project
 from api.models.submission import Submission
@@ -25,10 +20,6 @@
 from rest_framework.response import Response
 from rest_framework.viewsets import GenericViewSet
 
-
-logger = logging.getLogger("ypovoli")
-
-
 # TODO: Error message when creating a project with wrongly formatted date looks a bit weird
 class ProjectViewSet(RetrieveModelMixin,
                      UpdateModelMixin,
@@ -168,8 +159,6 @@ def _add_extra_check(self, request: Request, **_):
 
         project: Project = self.get_object()
 
-        logger.info(request.POST.dict())
-
         serializer = ExtraCheckSerializer(
             data=request.data,
             context={
@@ -179,7 +168,7 @@ def _add_extra_check(self, request: Request, **_):
         )
 
         if serializer.is_valid(raise_exception=True):
-            serializer.save(project=project, docker_image_id=request.data.get('docker_image'))
+            serializer.save(project=project)
 
         return Response({
             "message": gettext("project.success.extra_check.add")