diff --git a/lib/util.py b/lib/util.py
index fbc1acfa5..70aaa59ca 100644
--- a/lib/util.py
+++ b/lib/util.py
@@ -361,6 +361,8 @@ block_explorer_info = {
                         {'tx': 'tx', 'addr': 'address'}),
     'TradeBlock.com': ('https://tradeblock.com/blockchain',
                         {'tx': 'tx', 'addr': 'address'}),
+    'system default': ('blockchain:',
+                        {'tx': 'tx', 'addr': 'address'}),
 }
 
 def block_explorer(config):