diff --git a/core/types/gen_log_json.go b/core/types/gen_log_json.go
index cb0071938d..c9bdff5b38 100644
--- a/core/types/gen_log_json.go
+++ b/core/types/gen_log_json.go
@@ -12,6 +12,7 @@ import (
 
 var _ = (*logMarshaling)(nil)
 
+// MarshalJSON marshals as JSON.
 func (l Log) MarshalJSON() ([]byte, error) {
 	type Log struct {
 		Address     common.Address `json:"address" gencodec:"required"`
@@ -19,9 +20,9 @@ func (l Log) MarshalJSON() ([]byte, error) {
 		Data        hexutil.Bytes  `json:"data" gencodec:"required"`
 		BlockNumber hexutil.Uint64 `json:"blockNumber"`
 		TxHash      common.Hash    `json:"transactionHash" gencodec:"required"`
-		TxIndex     hexutil.Uint   `json:"transactionIndex" gencodec:"required"`
+		TxIndex     hexutil.Uint   `json:"transactionIndex"`
 		BlockHash   common.Hash    `json:"blockHash"`
-		Index       hexutil.Uint   `json:"logIndex" gencodec:"required"`
+		Index       hexutil.Uint   `json:"logIndex"`
 		Removed     bool           `json:"removed"`
 	}
 	var enc Log
@@ -37,6 +38,7 @@ func (l Log) MarshalJSON() ([]byte, error) {
 	return json.Marshal(&enc)
 }
 
+// UnmarshalJSON unmarshals from JSON.
 func (l *Log) UnmarshalJSON(input []byte) error {
 	type Log struct {
 		Address     *common.Address `json:"address" gencodec:"required"`
@@ -44,9 +46,9 @@ func (l *Log) UnmarshalJSON(input []byte) error {
 		Data        *hexutil.Bytes  `json:"data" gencodec:"required"`
 		BlockNumber *hexutil.Uint64 `json:"blockNumber"`
 		TxHash      *common.Hash    `json:"transactionHash" gencodec:"required"`
-		TxIndex     *hexutil.Uint   `json:"transactionIndex" gencodec:"required"`
+		TxIndex     *hexutil.Uint   `json:"transactionIndex"`
 		BlockHash   *common.Hash    `json:"blockHash"`
-		Index       *hexutil.Uint   `json:"logIndex" gencodec:"required"`
+		Index       *hexutil.Uint   `json:"logIndex"`
 		Removed     *bool           `json:"removed"`
 	}
 	var dec Log
@@ -72,17 +74,15 @@ func (l *Log) UnmarshalJSON(input []byte) error {
 		return errors.New("missing required field 'transactionHash' for Log")
 	}
 	l.TxHash = *dec.TxHash
-	if dec.TxIndex == nil {
-		return errors.New("missing required field 'transactionIndex' for Log")
+	if dec.TxIndex != nil {
+		l.TxIndex = uint(*dec.TxIndex)
 	}
-	l.TxIndex = uint(*dec.TxIndex)
 	if dec.BlockHash != nil {
 		l.BlockHash = *dec.BlockHash
 	}
-	if dec.Index == nil {
-		return errors.New("missing required field 'logIndex' for Log")
+	if dec.Index != nil {
+		l.Index = uint(*dec.Index)
 	}
-	l.Index = uint(*dec.Index)
 	if dec.Removed != nil {
 		l.Removed = *dec.Removed
 	}
diff --git a/core/types/log.go b/core/types/log.go
index d459d2892f..cf1dbc4ecb 100644
--- a/core/types/log.go
+++ b/core/types/log.go
@@ -45,11 +45,11 @@ type Log struct {
 	// hash of the transaction
 	TxHash common.Hash `json:"transactionHash" gencodec:"required"`
 	// index of the transaction in the block
-	TxIndex uint `json:"transactionIndex" gencodec:"required"`
+	TxIndex uint `json:"transactionIndex"`
 	// hash of the block in which the transaction was included
 	BlockHash common.Hash `json:"blockHash"`
 	// index of the log in the receipt
-	Index uint `json:"logIndex" gencodec:"required"`
+	Index uint `json:"logIndex"`
 
 	// The Removed field is true if this log was reverted due to a chain reorganisation.
 	// You must pay attention to this field if you receive logs through a filter query.
diff --git a/ethclient/ethclient.go b/ethclient/ethclient.go
index 592b7db356..7e3a439327 100644
--- a/ethclient/ethclient.go
+++ b/ethclient/ethclient.go
@@ -273,10 +273,15 @@ func (ec *Client) GetTransactionReceiptResult(ctx context.Context, txHash common
 	}
 	return r, result, err
 }
+
 func toBlockNumArg(number *big.Int) string {
 	if number == nil {
 		return "latest"
 	}
+	pending := big.NewInt(-1)
+	if number.Cmp(pending) == 0 {
+		return "pending"
+	}
 	return hexutil.EncodeBig(number)
 }