diff --git a/anatomy/views.py b/anatomy/views.py
index 0c37df3c..0bf800e1 100644
--- a/anatomy/views.py
+++ b/anatomy/views.py
@@ -101,7 +101,7 @@ def question_list(request):
 def question_detail(request, pk):
     question = get_object_or_404(AnatomyQuestion, pk=pk)
 
-    if not question.open_access and (not request.user.groups.filter(name="anatomy_checker").exists() and request.user not in question.author):
+    if not question.open_access and (not request.user.groups.filter(name="anatomy_checker").exists() and request.user not in question.author.all()):
         raise PermissionDenied()
 
     return render(request, "anatomy/question_detail.html", {"question": question})