diff --git a/plinth/__main__.py b/plinth/__main__.py
index 328484c17..d23a3d1a2 100644
--- a/plinth/__main__.py
+++ b/plinth/__main__.py
@@ -26,6 +26,7 @@ import logging
 import os
 import stat
 import sys
+import warnings
 
 import cherrypy
 
@@ -82,6 +83,15 @@ def setup_logging():
     cherrypy.log.error_file = cfg.status_log_file
     cherrypy.log.access_file = cfg.access_log_file
 
+    # Capture all Python warnings such as deprecation warnings
+    logging.captureWarnings(True)
+
+    # Log all deprecation warnings when in debug mode
+    if cfg.debug:
+        warnings.filterwarnings('default', '', DeprecationWarning)
+        warnings.filterwarnings('default', '', PendingDeprecationWarning)
+        warnings.filterwarnings('default', '', ImportWarning)
+
 
 def setup_server():
     """Setup CherryPy server"""