diff --git a/netbox/secrets/admin.py b/netbox/secrets/admin.py
index 3780dccd2..ac7a91fd6 100644
--- a/netbox/secrets/admin.py
+++ b/netbox/secrets/admin.py
@@ -42,13 +42,15 @@ class UserKeyAdmin(admin.ModelAdmin):
         if 'activate' in request.POST:
             form = ActivateUserKeyForm(request.POST)
             if form.is_valid():
-                try:
-                    master_key = my_userkey.get_master_key(form.cleaned_data['secret_key'])
+                master_key = my_userkey.get_master_key(form.cleaned_data['secret_key'])
+                if master_key is not None:
                     for uk in form.cleaned_data['_selected_action']:
                         uk.activate(master_key)
                     return redirect('admin:secrets_userkey_changelist')
-                except ValueError:
-                    messages.error(request, "Invalid private key provided. Unable to retrieve master key.")
+                else:
+                    messages.error(
+                        request, "Invalid private key provided. Unable to retrieve master key.", extra_tags='error'
+                    )
         else:
             form = ActivateUserKeyForm(initial={'_selected_action': request.POST.getlist(admin.ACTION_CHECKBOX_NAME)})