diff --git a/lib/masterd/iallocator.py b/lib/masterd/iallocator.py
index 45b0ba1b538806741f5218cf3fce4802a164a1e6..b6a8afdc62e90a6675302f3a7302978cd8b00b58 100644
--- a/lib/masterd/iallocator.py
+++ b/lib/masterd/iallocator.py
@@ -458,7 +458,7 @@ class IAllocator(object):
       "name": gdata.name,
       "alloc_policy": gdata.alloc_policy,
       "ipolicy": gmi.CalculateGroupIPolicy(cluster, gdata),
-      "tags": list(gdata.tags),
+      "tags": list(gdata.GetTags()),
       })
       for guuid, gdata in cfg.GetAllNodeGroupsInfo().items())