diff --git a/ereuse_devicehub/resources/action/views/trade.py b/ereuse_devicehub/resources/action/views/trade.py
index af44cedb..16f2572b 100644
--- a/ereuse_devicehub/resources/action/views/trade.py
+++ b/ereuse_devicehub/resources/action/views/trade.py
@@ -66,7 +66,7 @@ class TradeView():
 
         # check than the user than want to do the action is one of the users
         # involved in the action
-        if not g.user in [self.trade.user_from, self.trade.user_to]:
+        if g.user not in [self.trade.user_from, self.trade.user_to]:
             txt = "You do not participate in this trading"
             raise ValidationError(txt)