diff --git a/docs/strategy-advanced.md b/docs/strategy-advanced.md
index 417218bc3..52879c7b4 100644
--- a/docs/strategy-advanced.md
+++ b/docs/strategy-advanced.md
@@ -40,7 +40,6 @@ class AwesomeStrategy(IStrategy):
 !!! Note
     If the data is pair-specific, make sure to use pair as one of the keys in the dictionary.
 
-
 ## Dataframe access
 
 You may access dataframe in various strategy functions by querying it from dataprovider.
@@ -65,8 +64,9 @@ class AwesomeStrategy(IStrategy):
         trade_date = timeframe_to_prev_date(self.timeframe, trade.open_date_utc)
         # Look up trade candle.
         trade_candle = dataframe.loc[dataframe['date'] == trade_date]
-        # trade_candle may be None for trades that just opened as it is still incomplete.
-        if trade_candle is not None:
+        # trade_candle may be empty for trades that just opened as it is still incomplete.
+        if trade_candle.empty:
+            trade_candle = trade_candle.squeeze()
             # <...>
 ```