diff --git a/ethrpc_test.go b/ethrpc_test.go
index a004a0a..7c9cd43 100644
--- a/ethrpc_test.go
+++ b/ethrpc_test.go
@@ -526,10 +526,7 @@ func (s *EthRPCTestSuite) TestSendTransaction() {
 	httpmock.Reset()
 	s.registerResponse(fmt.Sprintf(`"%s"`, result), func(body []byte) {
 		s.methodEqual(body, "eth_sendTransaction")
-		s.paramsEqual(body, `[{
-			"from": ""
-		}]`)
-
+		s.paramsEqual(body,`[{}]`)
 	})
 
 	txid, err = s.rpc.EthSendTransaction(t)
diff --git a/types.go b/types.go
index b90baee..1af7d63 100644
--- a/types.go
+++ b/types.go
@@ -41,12 +41,13 @@ type T struct {
 
 // MarshalJSON implements the json.Unmarshaler interface.
 func (t T) MarshalJSON() ([]byte, error) {
-	params := map[string]interface{}{
-		"from": t.From,
-	}
+	params := map[string]interface{}{}
 	if t.To != "" {
 		params["to"] = t.To
 	}
+	if t.From != "" {
+		params["from"] = t.From
+	}
 	if t.Gas > 0 {
 		params["gas"] = IntToHex(t.Gas)
 	}