diff --git a/rpc/response.go b/rpc/response.go
index 5a4bc17..4766f2b 100644
--- a/rpc/response.go
+++ b/rpc/response.go
@@ -183,15 +183,16 @@ func (v *InfoGetDeployResult) UnmarshalJSON(data []byte) error {
 
 	if !strings.HasPrefix(version.ApiVersion, "2") {
 		var v1Compatible infoGetDeployResultV1Compatible
-		if err := json.Unmarshal(data, &v1Compatible); err == nil {
-			*v = InfoGetDeployResult{
-				ApiVersion:       v1Compatible.ApiVersion,
-				Deploy:           v1Compatible.Deploy,
-				ExecutionResults: types.DeployExecutionInfoFromV1(v1Compatible.ExecutionResults, v1Compatible.BlockHeight),
-				rawJSON:          data,
-			}
-			return nil
+		if err := json.Unmarshal(data, &v1Compatible); err != nil {
+			return err
 		}
+		*v = InfoGetDeployResult{
+			ApiVersion:       v1Compatible.ApiVersion,
+			Deploy:           v1Compatible.Deploy,
+			ExecutionResults: types.DeployExecutionInfoFromV1(v1Compatible.ExecutionResults, v1Compatible.BlockHeight),
+			rawJSON:          data,
+		}
+		return nil
 	}
 
 	var resp struct {
diff --git a/types/execution_result.go b/types/execution_result.go
index 6f6dd22..17e2fe2 100644
--- a/types/execution_result.go
+++ b/types/execution_result.go
@@ -152,14 +152,16 @@ func NewExecutionResultFromV1(v1 ExecutionResultV1) ExecutionResult {
 				Kind: TransformKind(transform.Transform),
 			})
 		}
-	}
 
-	return ExecutionResult{
-		ErrorMessage:            &v1.Failure.ErrorMessage,
-		Consumed:                v1.Failure.Cost,
-		Effects:                 transforms,
-		originExecutionResultV1: &v1,
+		return ExecutionResult{
+			ErrorMessage:            &v1.Failure.ErrorMessage,
+			Consumed:                v1.Failure.Cost,
+			Effects:                 transforms,
+			originExecutionResultV1: &v1,
+		}
 	}
+
+	return ExecutionResult{}
 }
 
 // ExecutionResultV2 represents the result of executing a single deploy for V2 version
diff --git a/types/transaction_scheduling.go b/types/transaction_scheduling.go
index bcfdbc7..86e2c04 100644
--- a/types/transaction_scheduling.go
+++ b/types/transaction_scheduling.go
@@ -3,6 +3,7 @@ package types
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"time"
 
 	"github.com/make-software/casper-go-sdk/v2/types/clvalue"
@@ -73,14 +74,17 @@ func (t *TransactionScheduling) UnmarshalJSON(data []byte) error {
 	}
 
 	var key string
-	if err := json.Unmarshal(data, &key); err == nil && key == "Standard" {
+	if err := json.Unmarshal(data, &key); err != nil {
+		return err
+	}
+	if key == "Standard" {
 		*t = TransactionScheduling{
 			Standard: &struct{}{},
 		}
 		return nil
 	}
 
-	return nil
+	return fmt.Errorf("unknown transaction scheduling type: %s", key)
 }
 
 func (t TransactionScheduling) MarshalJSON() ([]byte, error) {
diff --git a/types/transaction_target.go b/types/transaction_target.go
index 27509eb..860592a 100644
--- a/types/transaction_target.go
+++ b/types/transaction_target.go
@@ -4,6 +4,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"errors"
+	"fmt"
 
 	"github.com/make-software/casper-go-sdk/v2/types/clvalue"
 	"github.com/make-software/casper-go-sdk/v2/types/key"
@@ -104,14 +105,17 @@ func (t *TransactionTarget) UnmarshalJSON(data []byte) error {
 	}
 
 	var key string
-	if err := json.Unmarshal(data, &key); err == nil && key == "Native" {
+	if err := json.Unmarshal(data, &key); err != nil {
+		return err
+	}
+	if key == "Native" {
 		*t = TransactionTarget{
 			Native: &struct{}{},
 		}
 		return nil
 	}
 
-	return nil
+	return fmt.Errorf("unknown transaction target type: %s", key)
 }
 
 func (t TransactionTarget) MarshalJSON() ([]byte, error) {