diff --git a/consensus/mempool_test.go b/consensus/mempool_test.go
index e4d09c95..089d7b3f 100644
--- a/consensus/mempool_test.go
+++ b/consensus/mempool_test.go
@@ -2,6 +2,7 @@ package consensus
 
 import (
 	"encoding/binary"
+	"fmt"
 	"testing"
 	"time"
 
@@ -188,33 +189,41 @@ func (app *CounterApplication) Info(req abci.RequestInfo) abci.ResponseInfo {
 	return abci.ResponseInfo{Data: cmn.Fmt("txs:%v", app.txCount)}
 }
 
-func (app *CounterApplication) DeliverTx(tx []byte) abci.Result {
-	return runTx(tx, &app.txCount)
+func (app *CounterApplication) DeliverTx(tx []byte) abci.ResponseDeliverTx {
+	txValue := txAsUint64(tx)
+	if txValue != uint64(app.txCount) {
+		return abci.ResponseDeliverTx{
+			Code: abci.CodeType_BadNonce,
+			Log:  fmt.Sprintf("Invalid nonce. Expected %v, got %v", app.txCount, txValue)}
+	}
+	app.txCount += 1
+	return abci.ResponseDeliverTx{Code: abci.CodeType_OK}
 }
 
-func (app *CounterApplication) CheckTx(tx []byte) abci.Result {
-	return runTx(tx, &app.mempoolTxCount)
+func (app *CounterApplication) CheckTx(tx []byte) abci.ResponseCheckTx {
+	txValue := txAsUint64(tx)
+	if txValue != uint64(app.mempoolTxCount) {
+		return abci.ResponseCheckTx{
+			Code: abci.CodeType_BadNonce,
+			Log:  fmt.Sprintf("Invalid nonce. Expected %v, got %v", app.mempoolTxCount, txValue)}
+	}
+	app.mempoolTxCount += 1
+	return abci.ResponseCheckTx{Code: abci.CodeType_OK}
 }
 
-func runTx(tx []byte, countPtr *int) abci.Result {
-	count := *countPtr
+func txAsUint64(tx []byte) uint64 {
 	tx8 := make([]byte, 8)
 	copy(tx8[len(tx8)-len(tx):], tx)
-	txValue := binary.BigEndian.Uint64(tx8)
-	if txValue != uint64(count) {
-		return abci.ErrBadNonce.AppendLog(cmn.Fmt("Invalid nonce. Expected %v, got %v", count, txValue))
-	}
-	*countPtr += 1
-	return abci.OK
+	return binary.BigEndian.Uint64(tx8)
 }
 
-func (app *CounterApplication) Commit() abci.Result {
+func (app *CounterApplication) Commit() abci.ResponseCommit {
 	app.mempoolTxCount = app.txCount
 	if app.txCount == 0 {
-		return abci.OK
+		return abci.ResponseCommit{Code: abci.CodeType_OK}
 	} else {
 		hash := make([]byte, 8)
 		binary.BigEndian.PutUint64(hash, uint64(app.txCount))
-		return abci.NewResultOK(hash, "")
+		return abci.ResponseCommit{Code: abci.CodeType_OK, Data: hash}
 	}
 }
diff --git a/consensus/replay.go b/consensus/replay.go
index 38a5eef3..853d3a8d 100644
--- a/consensus/replay.go
+++ b/consensus/replay.go
@@ -385,22 +385,17 @@ type mockProxyApp struct {
 	abciResponses *sm.ABCIResponses
 }
 
-func (mock *mockProxyApp) DeliverTx(tx []byte) abci.Result {
+func (mock *mockProxyApp) DeliverTx(tx []byte) abci.ResponseDeliverTx {
 	r := mock.abciResponses.DeliverTx[mock.txCount]
 	mock.txCount += 1
-	return abci.Result{
-		r.Code,
-		r.Data,
-		r.Log,
-		r.Tags,
-	}
+	return *r
 }
 
 func (mock *mockProxyApp) EndBlock(height uint64) abci.ResponseEndBlock {
 	mock.txCount = 0
-	return mock.abciResponses.EndBlock
+	return *mock.abciResponses.EndBlock
 }
 
-func (mock *mockProxyApp) Commit() abci.Result {
-	return abci.NewResultOK(mock.appHash, "")
+func (mock *mockProxyApp) Commit() abci.ResponseCommit {
+	return abci.ResponseCommit{Code: abci.CodeType_OK, Data: mock.appHash}
 }
diff --git a/glide.lock b/glide.lock
index ccb74759..09f9ad2b 100644
--- a/glide.lock
+++ b/glide.lock
@@ -98,7 +98,7 @@ imports:
   - leveldb/table
   - leveldb/util
 - name: github.com/tendermint/abci
-  version: 6b47155e08732f46dafdcef185d23f0ff9ff24a5
+  version: 2cfad8523a54d64271d7cbc69a39433eab918aa0
   subpackages:
   - client
   - example/counter
diff --git a/glide.yaml b/glide.yaml
index 19485fb6..a20e76db 100644
--- a/glide.yaml
+++ b/glide.yaml
@@ -18,7 +18,7 @@ import:
 - package: github.com/spf13/viper
   version: v1.0.0
 - package: github.com/tendermint/abci
-  version: 6b47155e08732f46dafdcef185d23f0ff9ff24a5
+  version: 2cfad8523a54d64271d7cbc69a39433eab918aa0
   subpackages:
   - client
   - example/dummy
diff --git a/mempool/mempool_test.go b/mempool/mempool_test.go
index 2bbf9944..aa19e380 100644
--- a/mempool/mempool_test.go
+++ b/mempool/mempool_test.go
@@ -172,13 +172,19 @@ func TestSerialReap(t *testing.T) {
 		for i := start; i < end; i++ {
 			txBytes := make([]byte, 8)
 			binary.BigEndian.PutUint64(txBytes, uint64(i))
-			res := appConnCon.DeliverTxSync(txBytes)
-			if !res.IsOK() {
+			res, err := appConnCon.DeliverTxSync(txBytes)
+			if err != nil {
+				t.Errorf("Client error committing tx: %v", err)
+			}
+			if res.IsErr() {
 				t.Errorf("Error committing tx. Code:%v result:%X log:%v",
 					res.Code, res.Data, res.Log)
 			}
 		}
-		res := appConnCon.CommitSync()
+		res, err := appConnCon.CommitSync()
+		if err != nil {
+			t.Errorf("Client error committing: %v", err)
+		}
 		if len(res.Data) != 8 {
 			t.Errorf("Error committing. Hash:%X log:%v", res.Data, res.Log)
 		}
diff --git a/proxy/app_conn.go b/proxy/app_conn.go
index 9121e8db..49c88a37 100644
--- a/proxy/app_conn.go
+++ b/proxy/app_conn.go
@@ -12,12 +12,12 @@ type AppConnConsensus interface {
 	SetResponseCallback(abcicli.Callback)
 	Error() error
 
-	InitChainSync(types.RequestInitChain) (err error)
+	InitChainSync(types.RequestInitChain) error
 
-	BeginBlockSync(types.RequestBeginBlock) (err error)
+	BeginBlockSync(types.RequestBeginBlock) error
 	DeliverTxAsync(tx []byte) *abcicli.ReqRes
-	EndBlockSync(height uint64) (types.ResponseEndBlock, error)
-	CommitSync() (res types.Result)
+	EndBlockSync(height uint64) (*types.ResponseEndBlock, error)
+	CommitSync() (*types.ResponseCommit, error)
 }
 
 type AppConnMempool interface {
@@ -33,9 +33,9 @@ type AppConnMempool interface {
 type AppConnQuery interface {
 	Error() error
 
-	EchoSync(string) (res types.Result)
-	InfoSync(types.RequestInfo) (types.ResponseInfo, error)
-	QuerySync(types.RequestQuery) (types.ResponseQuery, error)
+	EchoSync(string) (*types.ResponseEcho, error)
+	InfoSync(types.RequestInfo) (*types.ResponseInfo, error)
+	QuerySync(types.RequestQuery) (*types.ResponseQuery, error)
 
 	//	SetOptionSync(key string, value string) (res types.Result)
 }
@@ -61,11 +61,11 @@ func (app *appConnConsensus) Error() error {
 	return app.appConn.Error()
 }
 
-func (app *appConnConsensus) InitChainSync(req types.RequestInitChain) (err error) {
+func (app *appConnConsensus) InitChainSync(req types.RequestInitChain) error {
 	return app.appConn.InitChainSync(req)
 }
 
-func (app *appConnConsensus) BeginBlockSync(req types.RequestBeginBlock) (err error) {
+func (app *appConnConsensus) BeginBlockSync(req types.RequestBeginBlock) error {
 	return app.appConn.BeginBlockSync(req)
 }
 
@@ -73,11 +73,11 @@ func (app *appConnConsensus) DeliverTxAsync(tx []byte) *abcicli.ReqRes {
 	return app.appConn.DeliverTxAsync(tx)
 }
 
-func (app *appConnConsensus) EndBlockSync(height uint64) (types.ResponseEndBlock, error) {
+func (app *appConnConsensus) EndBlockSync(height uint64) (*types.ResponseEndBlock, error) {
 	return app.appConn.EndBlockSync(height)
 }
 
-func (app *appConnConsensus) CommitSync() (res types.Result) {
+func (app *appConnConsensus) CommitSync() (*types.ResponseCommit, error) {
 	return app.appConn.CommitSync()
 }
 
@@ -131,14 +131,14 @@ func (app *appConnQuery) Error() error {
 	return app.appConn.Error()
 }
 
-func (app *appConnQuery) EchoSync(msg string) (res types.Result) {
+func (app *appConnQuery) EchoSync(msg string) (*types.ResponseEcho, error) {
 	return app.appConn.EchoSync(msg)
 }
 
-func (app *appConnQuery) InfoSync(req types.RequestInfo) (types.ResponseInfo, error) {
+func (app *appConnQuery) InfoSync(req types.RequestInfo) (*types.ResponseInfo, error) {
 	return app.appConn.InfoSync(req)
 }
 
-func (app *appConnQuery) QuerySync(reqQuery types.RequestQuery) (types.ResponseQuery, error) {
+func (app *appConnQuery) QuerySync(reqQuery types.RequestQuery) (*types.ResponseQuery, error) {
 	return app.appConn.QuerySync(reqQuery)
 }
diff --git a/proxy/app_conn_test.go b/proxy/app_conn_test.go
index 3c00f1ae..0fbad602 100644
--- a/proxy/app_conn_test.go
+++ b/proxy/app_conn_test.go
@@ -17,7 +17,7 @@ import (
 type AppConnTest interface {
 	EchoAsync(string) *abcicli.ReqRes
 	FlushSync() error
-	InfoSync(types.RequestInfo) (types.ResponseInfo, error)
+	InfoSync(types.RequestInfo) (*types.ResponseInfo, error)
 }
 
 type appConnTest struct {
@@ -36,7 +36,7 @@ func (app *appConnTest) FlushSync() error {
 	return app.appConn.FlushSync()
 }
 
-func (app *appConnTest) InfoSync(req types.RequestInfo) (types.ResponseInfo, error) {
+func (app *appConnTest) InfoSync(req types.RequestInfo) (*types.ResponseInfo, error) {
 	return app.appConn.InfoSync(req)
 }
 
diff --git a/rpc/client/mock/abci.go b/rpc/client/mock/abci.go
index e935a282..2ffa9269 100644
--- a/rpc/client/mock/abci.go
+++ b/rpc/client/mock/abci.go
@@ -38,7 +38,7 @@ func (a ABCIApp) ABCIQueryWithOptions(path string, data data.Bytes, opts client.
 func (a ABCIApp) BroadcastTxCommit(tx types.Tx) (*ctypes.ResultBroadcastTxCommit, error) {
 	res := ctypes.ResultBroadcastTxCommit{}
 	res.CheckTx = a.App.CheckTx(tx)
-	if !res.CheckTx.IsOK() {
+	if res.CheckTx.IsErr() {
 		return &res, nil
 	}
 	res.DeliverTx = a.App.DeliverTx(tx)
@@ -48,7 +48,7 @@ func (a ABCIApp) BroadcastTxCommit(tx types.Tx) (*ctypes.ResultBroadcastTxCommit
 func (a ABCIApp) BroadcastTxAsync(tx types.Tx) (*ctypes.ResultBroadcastTx, error) {
 	c := a.App.CheckTx(tx)
 	// and this gets written in a background thread...
-	if c.IsOK() {
+	if !c.IsErr() {
 		go func() { a.App.DeliverTx(tx) }() // nolint: errcheck
 	}
 	return &ctypes.ResultBroadcastTx{c.Code, c.Data, c.Log, tx.Hash()}, nil
@@ -57,7 +57,7 @@ func (a ABCIApp) BroadcastTxAsync(tx types.Tx) (*ctypes.ResultBroadcastTx, error
 func (a ABCIApp) BroadcastTxSync(tx types.Tx) (*ctypes.ResultBroadcastTx, error) {
 	c := a.App.CheckTx(tx)
 	// and this gets written in a background thread...
-	if c.IsOK() {
+	if !c.IsErr() {
 		go func() { a.App.DeliverTx(tx) }() // nolint: errcheck
 	}
 	return &ctypes.ResultBroadcastTx{c.Code, c.Data, c.Log, tx.Hash()}, nil
diff --git a/rpc/client/mock/abci_test.go b/rpc/client/mock/abci_test.go
index 36a45791..216bd7c2 100644
--- a/rpc/client/mock/abci_test.go
+++ b/rpc/client/mock/abci_test.go
@@ -37,8 +37,8 @@ func TestABCIMock(t *testing.T) {
 		BroadcastCommit: mock.Call{
 			Args: goodTx,
 			Response: &ctypes.ResultBroadcastTxCommit{
-				CheckTx:   abci.Result{Data: data.Bytes("stand")},
-				DeliverTx: abci.Result{Data: data.Bytes("deliver")},
+				CheckTx:   abci.ResponseCheckTx{Data: data.Bytes("stand")},
+				DeliverTx: abci.ResponseDeliverTx{Data: data.Bytes("deliver")},
 			},
 			Error: errors.New("bad tx"),
 		},
diff --git a/rpc/core/abci.go b/rpc/core/abci.go
index 564c0bc6..a64c3d29 100644
--- a/rpc/core/abci.go
+++ b/rpc/core/abci.go
@@ -93,5 +93,5 @@ func ABCIInfo() (*ctypes.ResultABCIInfo, error) {
 	if err != nil {
 		return nil, err
 	}
-	return &ctypes.ResultABCIInfo{resInfo}, nil
+	return &ctypes.ResultABCIInfo{*resInfo}, nil
 }
diff --git a/rpc/core/mempool.go b/rpc/core/mempool.go
index 72cf2865..857ea75b 100644
--- a/rpc/core/mempool.go
+++ b/rpc/core/mempool.go
@@ -177,8 +177,8 @@ func BroadcastTxCommit(tx types.Tx) (*ctypes.ResultBroadcastTxCommit, error) {
 	if checkTxR.Code != abci.CodeType_OK {
 		// CheckTx failed!
 		return &ctypes.ResultBroadcastTxCommit{
-			CheckTx:   checkTxR.Result(),
-			DeliverTx: abci.Result{},
+			CheckTx:   *checkTxR,
+			DeliverTx: abci.ResponseDeliverTx{},
 			Hash:      tx.Hash(),
 		}, nil
 	}
@@ -191,23 +191,23 @@ func BroadcastTxCommit(tx types.Tx) (*ctypes.ResultBroadcastTxCommit, error) {
 	case deliverTxResMsg := <-deliverTxResCh:
 		deliverTxRes := deliverTxResMsg.(types.TMEventData).Unwrap().(types.EventDataTx)
 		// The tx was included in a block.
-		deliverTxR := &abci.ResponseDeliverTx{
+		deliverTxR := abci.ResponseDeliverTx{
 			Code: deliverTxRes.Result.Code,
 			Data: deliverTxRes.Result.Data,
 			Log:  deliverTxRes.Result.Log,
 		}
 		logger.Info("DeliverTx passed ", "tx", data.Bytes(tx), "response", deliverTxR)
 		return &ctypes.ResultBroadcastTxCommit{
-			CheckTx:   checkTxR.Result(),
-			DeliverTx: deliverTxR.Result(),
+			CheckTx:   *checkTxR,
+			DeliverTx: deliverTxR,
 			Hash:      tx.Hash(),
 			Height:    deliverTxRes.Height,
 		}, nil
 	case <-timer.C:
 		logger.Error("failed to include tx")
 		return &ctypes.ResultBroadcastTxCommit{
-			CheckTx:   checkTxR.Result(),
-			DeliverTx: abci.Result{},
+			CheckTx:   *checkTxR,
+			DeliverTx: abci.ResponseDeliverTx{},
 			Hash:      tx.Hash(),
 		}, fmt.Errorf("Timed out waiting for transaction to be included in a block")
 	}
diff --git a/rpc/core/tx.go b/rpc/core/tx.go
index dc842e62..80d1cb32 100644
--- a/rpc/core/tx.go
+++ b/rpc/core/tx.go
@@ -94,7 +94,7 @@ func Tx(hash []byte, prove bool) (*ctypes.ResultTx, error) {
 	return &ctypes.ResultTx{
 		Height:   height,
 		Index:    index,
-		TxResult: r.Result.Result(),
+		TxResult: r.Result,
 		Tx:       r.Tx,
 		Proof:    proof,
 	}, nil
diff --git a/rpc/core/types/responses.go b/rpc/core/types/responses.go
index e4c5d8fc..a1b7e36f 100644
--- a/rpc/core/types/responses.go
+++ b/rpc/core/types/responses.go
@@ -104,18 +104,18 @@ type ResultBroadcastTx struct {
 }
 
 type ResultBroadcastTxCommit struct {
-	CheckTx   abci.Result `json:"check_tx"`
-	DeliverTx abci.Result `json:"deliver_tx"`
-	Hash      data.Bytes  `json:"hash"`
-	Height    uint64      `json:"height"`
+	CheckTx   abci.ResponseCheckTx   `json:"check_tx"`
+	DeliverTx abci.ResponseDeliverTx `json:"deliver_tx"`
+	Hash      data.Bytes             `json:"hash"`
+	Height    uint64                 `json:"height"`
 }
 
 type ResultTx struct {
-	Height   uint64        `json:"height"`
-	Index    uint32        `json:"index"`
-	TxResult abci.Result   `json:"tx_result"`
-	Tx       types.Tx      `json:"tx"`
-	Proof    types.TxProof `json:"proof,omitempty"`
+	Height   uint64                 `json:"height"`
+	Index    uint32                 `json:"index"`
+	TxResult abci.ResponseDeliverTx `json:"tx_result"`
+	Tx       types.Tx               `json:"tx"`
+	Proof    types.TxProof          `json:"proof,omitempty"`
 }
 
 type ResultUnconfirmedTxs struct {
diff --git a/state/execution.go b/state/execution.go
index be09b2b2..5b324eff 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -248,7 +248,11 @@ func (s *State) CommitStateUpdateMempool(proxyAppConn proxy.AppConnConsensus, bl
 	defer mempool.Unlock()
 
 	// Commit block, get hash back
-	res := proxyAppConn.CommitSync()
+	res, err := proxyAppConn.CommitSync()
+	if err != nil {
+		s.logger.Error("Client error during proxyAppConn.CommitSync", "err", err)
+		return err
+	}
 	if res.IsErr() {
 		s.logger.Error("Error in proxyAppConn.CommitSync", "err", res)
 		return res
@@ -275,7 +279,11 @@ func ExecCommitBlock(appConnConsensus proxy.AppConnConsensus, block *types.Block
 		return nil, err
 	}
 	// Commit block, get hash back
-	res := appConnConsensus.CommitSync()
+	res, err := appConnConsensus.CommitSync()
+	if err != nil {
+		logger.Error("Client error during proxyAppConn.CommitSync", "err", res)
+		return nil, err
+	}
 	if res.IsErr() {
 		logger.Error("Error in proxyAppConn.CommitSync", "err", res)
 		return nil, res
diff --git a/state/state.go b/state/state.go
index 1c2b3efe..e1f16835 100644
--- a/state/state.go
+++ b/state/state.go
@@ -279,7 +279,7 @@ type ABCIResponses struct {
 	Height int
 
 	DeliverTx []*abci.ResponseDeliverTx
-	EndBlock  abci.ResponseEndBlock
+	EndBlock  *abci.ResponseEndBlock
 
 	txs types.Txs // reference for indexing results by hash
 }
diff --git a/state/state_test.go b/state/state_test.go
index b60f1546..7fff0774 100644
--- a/state/state_test.go
+++ b/state/state_test.go
@@ -80,7 +80,7 @@ func TestABCIResponsesSaveLoad(t *testing.T) {
 	abciResponses := NewABCIResponses(block)
 	abciResponses.DeliverTx[0] = &abci.ResponseDeliverTx{Data: []byte("foo"), Tags: []*abci.KVPair{}}
 	abciResponses.DeliverTx[1] = &abci.ResponseDeliverTx{Data: []byte("bar"), Log: "ok", Tags: []*abci.KVPair{}}
-	abciResponses.EndBlock = abci.ResponseEndBlock{Diffs: []*abci.Validator{
+	abciResponses.EndBlock = &abci.ResponseEndBlock{Diffs: []*abci.Validator{
 		{
 			PubKey: crypto.GenPrivKeyEd25519().PubKey().Bytes(),
 			Power:  10,
@@ -198,12 +198,13 @@ func makeHeaderPartsResponses(state *State, height int,
 	block := makeBlock(height, state)
 	_, val := state.Validators.GetByIndex(0)
 	abciResponses := &ABCIResponses{
-		Height: height,
+		Height:   height,
+		EndBlock: &abci.ResponseEndBlock{Diffs: []*abci.Validator{}},
 	}
 
 	// if the pubkey is new, remove the old and add the new
 	if !bytes.Equal(pubkey.Bytes(), val.PubKey.Bytes()) {
-		abciResponses.EndBlock = abci.ResponseEndBlock{
+		abciResponses.EndBlock = &abci.ResponseEndBlock{
 			Diffs: []*abci.Validator{
 				{val.PubKey.Bytes(), 0},
 				{pubkey.Bytes(), 10},