diff --git a/catalyst/exchange/exchange_algorithm.py b/catalyst/exchange/exchange_algorithm.py
index 47a0214fe..ea173a042 100644
--- a/catalyst/exchange/exchange_algorithm.py
+++ b/catalyst/exchange/exchange_algorithm.py
@@ -1170,7 +1170,7 @@ def get_orderbook(self, asset, order_type='all', limit=None):
         asset: TradingPair
 
         order_type: str
-            The type of orders: bid, ask or all
+            The type of the orders: 'bids' or 'asks' or 'all'
 
         limit: int