diff --git a/plugins/org.python.pydev.core/pysrc/_pydevd_sys_monitoring/pydevd_sys_monitoring.py b/plugins/org.python.pydev.core/pysrc/_pydevd_sys_monitoring/pydevd_sys_monitoring.py
index ad96e95593..1db2429bda 100644
--- a/plugins/org.python.pydev.core/pysrc/_pydevd_sys_monitoring/pydevd_sys_monitoring.py
+++ b/plugins/org.python.pydev.core/pysrc/_pydevd_sys_monitoring/pydevd_sys_monitoring.py
@@ -4,7 +4,6 @@
 import re
 import sys
 import threading
-import traceback
 from types import CodeType
 from typing import Dict, Optional, Set
 
@@ -17,8 +16,9 @@
     get_abs_path_real_path_and_base_from_file, \
     get_abs_path_real_path_and_base_from_frame
 
-DEBUGGER_ID = sys.monitoring.DEBUGGER_ID
-monitor = sys.monitoring
+if hasattr(sys, 'monitoring'):
+    DEBUGGER_ID = sys.monitoring.DEBUGGER_ID
+    monitor = sys.monitoring
 
 _thread_local_info = threading.local()
 _get_ident = threading.get_ident
@@ -45,13 +45,6 @@
 DEBUG_START_PY3K = ('_pydev_execfile.py', 'execfile')
 TRACE_PROPERTY = 'pydevd_traceproperty.py'
 
-# Cache where we should keep that we completely skipped entering some context.
-# It needs to be invalidated when:
-# - Breakpoints are changed
-# It can be used when running regularly (without step over/step in/step return)
-global_cache_skips = {}
-global_cache_frame_skips = {}
-
 _global_notify_skipped_step_in = False
 _global_notify_skipped_step_in_lock = ForkSafeLock()
 
diff --git a/plugins/org.python.pydev.core/pysrc/pydevd.py b/plugins/org.python.pydev.core/pysrc/pydevd.py
index e44d6d7c62..e246e1a8dd 100644
--- a/plugins/org.python.pydev.core/pysrc/pydevd.py
+++ b/plugins/org.python.pydev.core/pysrc/pydevd.py
@@ -4,7 +4,6 @@
 This module starts the debugger.
 '''
 import sys  # @NoMove
-from _pydevd_sys_monitoring import pydevd_sys_monitoring
 if sys.version_info[:2] < (3, 6):
     raise RuntimeError('The PyDev.Debugger requires Python 3.6 onwards to be run. If you need to use an older Python version, use an older version of the debugger.')
 import os
@@ -99,6 +98,9 @@
 from _pydevd_bundle.pydevd_timeout import TimeoutTracker
 from _pydevd_bundle.pydevd_thread_lifecycle import suspend_all_threads, mark_thread_suspended
 
+if USE_SYS_MONITORING:
+    from _pydevd_sys_monitoring import pydevd_sys_monitoring
+
 pydevd_gevent_integration = None
 
 if SUPPORT_GEVENT: