diff --git a/iron_condor.py b/iron_condor.py
index 085693d..8429c17 100644
--- a/iron_condor.py
+++ b/iron_condor.py
@@ -174,7 +174,7 @@ def _enter_iron_condor(entry_time: datetime):
             {'Action': 'BUY', 'Strike': long_put_strike, 'Type': 'PUT'}
         ],
         'Open': put_spread_fill,
-        'Entry Slippage': round(put_spread_mid, put_spread_fill, 3)
+        'Entry Slippage': round(put_spread_mid - put_spread_fill, 3)
     }
 
     upsert(pd.DataFrame([{