diff --git a/devstack/log.py b/devstack/log.py
index c70249a1..0d989532 100644
--- a/devstack/log.py
+++ b/devstack/log.py
@@ -58,9 +58,11 @@ SysLogHandler = SysLogHandler
 def log_debug(f):
     @functools.wraps(f)
     def wrapper(*args, **kw):
-        logging.debug('%s(%s, %s) ->', f.func_name, str(args), str(kw))
+        if root.isEnabledFor(debug):
+            logging.debug('%s(%s, %s) ->', f.func_name, str(args), str(kw))
         rv = f(*args, **kw)
-        logging.debug(pprint.pformat(rv, indent=2))
-        logging.debug('')
+        if root.isEnabledFor(debug):
+            logging.debug(pprint.pformat(rv, indent=2))
+            logging.debug('')
         return rv
     return wrapper