diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM
index 234989847..df475690d 100644
--- a/WHATS_NEW_DM
+++ b/WHATS_NEW_DM
@@ -1,5 +1,6 @@
 Version 1.02.64 - 
 ===================================
+  Log debug open_count in _node_has_closed_parents().
   Change dm_report_field_string() API to accept const char *const *data.
 
 Version 1.02.63 - 9th February 2011
diff --git a/libdm/libdm-deptree.c b/libdm/libdm-deptree.c
index 8d0051494..8f51bf96b 100644
--- a/libdm/libdm-deptree.c
+++ b/libdm/libdm-deptree.c
@@ -938,8 +938,11 @@ static int _node_has_closed_parents(struct dm_tree_node *node,
 		    !info.exists)
 			continue;
 
-		if (info.open_count)
+		if (info.open_count) {
+			log_debug("Node %s %d:%d has open_count %d", uuid_prefix,
+				  dinfo->major, dinfo->minor, info.open_count);
 			return 0;
+		}
 	}
 
 	return 1;