diff --git a/graphql/graphql.go b/graphql/graphql.go
index 66c581628..ea587106b 100644
--- a/graphql/graphql.go
+++ b/graphql/graphql.go
@@ -301,21 +301,21 @@ func (t *Transaction) Status(ctx context.Context) (*hexutil.Uint64, error) {
 	return &ret, nil
 }
 
-func (t *Transaction) GasUsed(ctx context.Context) (*hexutil.Uint64, error) {
+func (t *Transaction) GasUsed(ctx context.Context) (*Long, error) {
 	receipt, err := t.getReceipt(ctx)
 	if err != nil || receipt == nil {
 		return nil, err
 	}
-	ret := hexutil.Uint64(receipt.GasUsed)
+	ret := Long(receipt.GasUsed)
 	return &ret, nil
 }
 
-func (t *Transaction) CumulativeGasUsed(ctx context.Context) (*hexutil.Uint64, error) {
+func (t *Transaction) CumulativeGasUsed(ctx context.Context) (*Long, error) {
 	receipt, err := t.getReceipt(ctx)
 	if err != nil || receipt == nil {
 		return nil, err
 	}
-	ret := hexutil.Uint64(receipt.CumulativeGasUsed)
+	ret := Long(receipt.CumulativeGasUsed)
 	return &ret, nil
 }
 
@@ -811,7 +811,7 @@ type CallData struct {
 // CallResult encapsulates the result of an invocation of the `call` accessor.
 type CallResult struct {
 	data    hexutil.Bytes  // The return data from the call
-	gasUsed hexutil.Uint64 // The amount of gas used
+	gasUsed Long           // The amount of gas used
 	status  hexutil.Uint64 // The return status of the call - 0 for failure or 1 for success.
 }
 
@@ -819,7 +819,7 @@ func (c *CallResult) Data() hexutil.Bytes {
 	return c.data
 }
 
-func (c *CallResult) GasUsed() hexutil.Uint64 {
+func (c *CallResult) GasUsed() Long {
 	return c.gasUsed
 }
 
@@ -847,22 +847,22 @@ func (b *Block) Call(ctx context.Context, args struct {
 
 	return &CallResult{
 		data:    result.ReturnData,
-		gasUsed: hexutil.Uint64(result.UsedGas),
+		gasUsed: Long(result.UsedGas),
 		status:  status,
 	}, nil
 }
 
 func (b *Block) EstimateGas(ctx context.Context, args struct {
 	Data ethapi.CallArgs
-}) (hexutil.Uint64, error) {
+}) (Long, error) {
 	if b.numberOrHash == nil {
 		_, err := b.resolveHeader(ctx)
 		if err != nil {
-			return hexutil.Uint64(0), err
+			return 0, err
 		}
 	}
 	gas, err := ethapi.DoEstimateGas(ctx, b.backend, args.Data, *b.numberOrHash, b.backend.RPCGasCap())
-	return gas, err
+	return Long(gas), err
 }
 
 type Pending struct {
@@ -917,16 +917,17 @@ func (p *Pending) Call(ctx context.Context, args struct {
 
 	return &CallResult{
 		data:    result.ReturnData,
-		gasUsed: hexutil.Uint64(result.UsedGas),
+		gasUsed: Long(result.UsedGas),
 		status:  status,
 	}, nil
 }
 
 func (p *Pending) EstimateGas(ctx context.Context, args struct {
 	Data ethapi.CallArgs
-}) (hexutil.Uint64, error) {
+}) (Long, error) {
 	pendingBlockNr := rpc.BlockNumberOrHashWithNumber(rpc.PendingBlockNumber)
-	return ethapi.DoEstimateGas(ctx, p.backend, args.Data, pendingBlockNr, p.backend.RPCGasCap())
+	gas, err := ethapi.DoEstimateGas(ctx, p.backend, args.Data, pendingBlockNr, p.backend.RPCGasCap())
+	return Long(gas), err
 }
 
 // Resolver is the top-level object in the GraphQL hierarchy.
diff --git a/graphql/graphql_test.go b/graphql/graphql_test.go
index 77129673c..fc62da181 100644
--- a/graphql/graphql_test.go
+++ b/graphql/graphql_test.go
@@ -117,6 +117,12 @@ func TestGraphQLBlockSerialization(t *testing.T) {
 			want: `{"errors":[{"message":"Cannot query field \"bleh\" on type \"Query\".","locations":[{"line":1,"column":2}]}]}`,
 			code: 400,
 		},
+		// should return `estimateGas` as decimal
+		{
+			body: `{"query": "{block{ estimateGas(data:{}) }}"}`,
+			want: `{"data":{"block":{"estimateGas":53000}}}`,
+			code: 200,
+		},
 	} {
 		resp, err := http.Post(fmt.Sprintf("http://%s/graphql", "127.0.0.1:9393"), "application/json", strings.NewReader(tt.body))
 		if err != nil {