diff --git a/check_server_compatibility.py b/check_server_compatibility.py
index 7d6e6d5..e5f3fd8 100755
--- a/check_server_compatibility.py
+++ b/check_server_compatibility.py
@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 import time
 import uuid
+import os
 from datetime import date
 from datetime import datetime
 from datetime import timedelta
@@ -77,11 +78,9 @@
 
 
 def _debugger():
-    import pdb
-
-    ## TODO: check some environmental flags
-    ## only hackers want the debug mode
-    pdb.set_trace()
+    if os.environ.get('PYTHON_CALDAV_DEBUGMODE') == "DEBUG_PDB":
+        import pdb
+        pdb.set_trace()
 
 
 def _delay_decorator(f, delay=10):
diff --git a/tests/compatibility_issues.py b/tests/compatibility_issues.py
index 16a4687..ccd5051 100644
--- a/tests/compatibility_issues.py
+++ b/tests/compatibility_issues.py
@@ -411,12 +411,13 @@
 nextcloud = [
     'date_search_ignores_duration',
     'sync_breaks_on_delete',
-    'no_recurring_todo',
     'combined_search_not_working',
     'text_search_is_exact_match_sometimes',
     'search_needs_comptype',
     'calendar_color',
-    'calendar_order'
+    'calendar_order',
+    'date_todo_search_ignores_duration',
+    'broken_expand_on_exceptions'
 ]
 
 fastmail = [