diff --git a/params/config.go b/params/config.go
index 2deea5b7f0..f7bbdf79b7 100644
--- a/params/config.go
+++ b/params/config.go
@@ -411,8 +411,10 @@ func (c *CliqueConfig) String() string {
 
 // OptimismConfig is the optimism config.
 type OptimismConfig struct {
-	BaseFeeRecipient common.Address `json:"baseFeeRecipient"`
-	L1FeeRecipient   common.Address `json:"l1FeeRecipient"`
+	BaseFeeRecipient   common.Address `json:"baseFeeRecipient"`
+	L1FeeRecipient     common.Address `json:"l1FeeRecipient"`
+	EIP1559Elasticity  uint64         `json:"eip1559Elasticity"`
+	EIP1559Denominator uint64         `json:"eip1559Denominator"`
 }
 
 // String implements the stringer interface, returning the optimism fee config details.