diff --git a/service/security_group.go b/service/security_group.go
index c2b7fad..c25665d 100644
--- a/service/security_group.go
+++ b/service/security_group.go
@@ -631,7 +631,7 @@ func (s *SecurityGroupService) DescribeSecurityGroupRules(i *DescribeSecurityGro
 type DescribeSecurityGroupRulesInput struct {
 
 	// Direction's available values: 0, 1
-	Direction          *int      `json:"direction" name:"direction" default:"0" location:"params"`
+	Direction          *int      `json:"direction" name:"direction" location:"params"`
 	Limit              *int      `json:"limit" name:"limit" default:"20" location:"params"`
 	Offset             *int      `json:"offset" name:"offset" default:"0" location:"params"`
 	SecurityGroup      *string   `json:"security_group" name:"security_group" location:"params"` // Required