diff --git a/radosgw_agent/worker.py b/radosgw_agent/worker.py
index 0087da6..cd7360c 100644
--- a/radosgw_agent/worker.py
+++ b/radosgw_agent/worker.py
@@ -71,7 +71,7 @@ def unlock_shard(self):
 
     def set_bound(self, key, marker, retries, type_=None):
         # api doesn't allow setting a bound with a blank marker
-        if marker:
+        if marker != ' ':
             if type_ is None:
                 type_ = self.type
             try: