diff --git a/client/transactions.go b/client/transactions.go
index 9a72c61..131e20b 100644
--- a/client/transactions.go
+++ b/client/transactions.go
@@ -159,7 +159,7 @@ func (c *Client) TransactionOutputsFromReferences(
 func (c *Client) EvaluateTx(
 	txCbor string,
 	AdditionalUtxos ...string,
-) ([]models.RedeemerEvaluation, error) {
+) (models.EvaluateTxResponse, error) {
 	url := "/transactions/evaluate"
 	body := models.EvaluateTx{
 		Cbor:            txCbor,
@@ -176,7 +176,7 @@ func (c *Client) EvaluateTx(
 		return nil, fmt.Errorf("unexpected error: %d", resp.Body)
 	}
 	defer resp.Body.Close()
-	var redeemerEvals []models.RedeemerEvaluation
+	var redeemerEvals models.EvaluateTxResponse
 	err = json.NewDecoder(resp.Body).Decode(&redeemerEvals)
 	if err != nil {
 		return nil, err
diff --git a/models/transactions.go b/models/transactions.go
index d04fc8d..95e4f21 100644
--- a/models/transactions.go
+++ b/models/transactions.go
@@ -92,8 +92,8 @@ type EvaluateTx struct {
 }
 
 type ExecutionUnits struct {
-	Mem   int64 `json:"Mem"`
-	Steps int64 `json:"Steps"`
+	Mem   int64 `json:"mem"`
+	Steps int64 `json:"steps"`
 }
 
 type RedeemerEvaluation struct {