diff --git a/chainqueue/runnable/list.py b/chainqueue/runnable/list.py
index 58cf450..379dd8c 100644
--- a/chainqueue/runnable/list.py
+++ b/chainqueue/runnable/list.py
@@ -41,7 +41,7 @@ argparser.add_argument('--include-pending', action='store_true', dest='include_p
 argparser.add_argument('--renderer', type=str, default=[], action='append', help='Transaction renderer for output')
 #argparser.add_argument('--summary', action='store_true', help='output summary for each status category')
 #argparser.add_argument('-o', '--column', dest='column', action='append', type=str, help='add a column to display')
-argparser.add_positional('address', type=str, help='Ethereum address of recipient')
+argparser.add_positional('address', required=False, type=str, help='Ethereum address of recipient')
 args = argparser.parse_args()
 extra_args = {
     'address': None,
diff --git a/chainqueue/store/base.py b/chainqueue/store/base.py
index 4ed8ee5..5cd048d 100644
--- a/chainqueue/store/base.py
+++ b/chainqueue/store/base.py
@@ -104,6 +104,7 @@ class Store:
             else:
                 for v in self.state_store.elements(state, numeric=True):
                     refs_state += self.state_store.list(v)
+                refs_state = list(set(refs_state))
         if include_pending:
             refs_state += self.state_store.list(0)