diff --git a/data/refdata/exchanges.cfg b/data/refdata/exchanges.cfg
index c6ac227..7f01a28 100644
--- a/data/refdata/exchanges.cfg
+++ b/data/refdata/exchanges.cfg
@@ -10,7 +10,7 @@
         # , "quote_asset":        "USD"
 
         "mktdata" : {
-            "class":  "cvttpy_trading.exchanges.coinbase.spot.mkt_data.XXXXXXXX"
+            "class":  "cvttpy_trading.exchanges.mkt_simulator.md_client.XXXXXXXX"
         },
         "order_entry": {
             "class":  "cvttpy_trading.exchanges.coinbase.spot.oe_client.CoinbaseSpotOEClient"