diff --git a/wiki_groups/views.py b/wiki_groups/views.py
index afda14f..e2055f1 100644
--- a/wiki_groups/views.py
+++ b/wiki_groups/views.py
@@ -91,8 +91,10 @@ class RemoveUserView(WikiGroupMixin, RedirectView):
         return reverse("wiki_groups:admin-group", args=[kwargs["pk"]])
 
     def get(self, request, *args, **kwargs):
-        user = User.objects.get(pk=kwargs["user_pk"])
-        self.object.users.remove(user)
+        user = User.objects.filter(pk=kwargs["user_pk"]).first()
+
+        if user is not None:
+            self.object.users.remove(user)
 
         return super().get(request, *args, **kwargs)
 
@@ -102,7 +104,11 @@ class RemoveManagerView(WikiGroupMixin, RedirectView):
         return reverse("wiki_groups:admin-group", args=[kwargs["pk"]])
 
     def get(self, request, *args, **kwargs):
-        user = User.objects.get(pk=kwargs["user_pk"])
+        user = User.objects.filter(pk=kwargs["user_pk"]).first()
+
+        if user is not None:
+            self.object.users.remove(user)
+
         self.object.managers.remove(user)
 
         return super().get(request, *args, **kwargs)
@@ -113,8 +119,10 @@ class RemoveGroupView(WikiGroupMixin, RedirectView):
         return reverse("wiki_groups:admin-group", args=[kwargs["pk"]])
 
     def get(self, request, *args, **kwargs):
-        group = WikiGroup.objects.get(pk=kwargs["group_pk"])
-        self.object.includes_groups.remove(group)
+        group = WikiGroup.objects.filter(pk=kwargs["group_pk"]).first()
+
+        if group is not None:
+            self.object.includes_groups.remove(group)
 
         return super().get(request, *args, **kwargs)