diff --git a/state/execution.go b/state/execution.go
index f38f5e0bb9a..90520a1fd4c 100644
--- a/state/execution.go
+++ b/state/execution.go
@@ -86,6 +86,9 @@ func (blockExec *BlockExecutor) ApplyBlock(state State, blockID types.BlockID, b
 	fail.Fail() // XXX
 
 	// update the state with the block and responses
+	////////////////////  iris/tendermint begin  ///////////////////////////
+	preState := state.Copy()
+	////////////////////  iris/tendermint end  ///////////////////////////
 	state, err = updateState(state, blockID, &block.Header, abciResponses)
 	if err != nil {
 		return state, fmt.Errorf("Commit failed for application: %v", err)
@@ -105,6 +108,9 @@ func (blockExec *BlockExecutor) ApplyBlock(state State, blockID types.BlockID, b
 	// update the app hash and save the state
 	state.AppHash = appHash
 	SaveState(blockExec.db, state)
+	////////////////////  iris/tendermint begin  ///////////////////////////
+	SavePreState(blockExec.db, preState)
+	////////////////////  iris/tendermint end  ///////////////////////////
 
 	fail.Fail() // XXX
 
diff --git a/state/state.go b/state/state.go
index fb589a2404b..6dd8e0d610d 100644
--- a/state/state.go
+++ b/state/state.go
@@ -12,6 +12,9 @@ import (
 // database keys
 var (
 	stateKey = []byte("stateKey")
+	////////////////////  iris/tendermint begin  ///////////////////////////
+	statePreKey = []byte("statePreKey")
+	////////////////////  iris/tendermint end  ///////////////////////////
 )
 
 //-----------------------------------------------------------------------------
diff --git a/state/store.go b/state/store.go
index 9e94e36faab..a5a311a6186 100644
--- a/state/store.go
+++ b/state/store.go
@@ -62,6 +62,12 @@ func LoadState(db dbm.DB) State {
 	return loadState(db, stateKey)
 }
 
+////////////////////  iris/tendermint begin  ///////////////////////////
+func LoadPreState(db dbm.DB) State {
+	return loadState(db, statePreKey)
+}
+////////////////////  iris/tendermint end  ///////////////////////////
+
 func loadState(db dbm.DB, key []byte) (state State) {
 	buf := db.Get(key)
 	if len(buf) == 0 {
@@ -84,11 +90,19 @@ func SaveState(db dbm.DB, state State) {
 	saveState(db, state, stateKey)
 }
 
+////////////////////  iris/tendermint begin  ///////////////////////////
+func SavePreState(db dbm.DB, state State) {
+	saveState(db, state, statePreKey)
+}
+////////////////////  iris/tendermint end  ///////////////////////////
+
 func saveState(db dbm.DB, state State, key []byte) {
 	nextHeight := state.LastBlockHeight + 1
 	saveValidatorsInfo(db, nextHeight, state.LastHeightValidatorsChanged, state.Validators)
 	saveConsensusParamsInfo(db, nextHeight, state.LastHeightConsensusParamsChanged, state.ConsensusParams)
-	db.SetSync(stateKey, state.Bytes())
+	////////////////////  iris/tendermint begin  ///////////////////////////
+	db.SetSync(key, state.Bytes())
+	////////////////////  iris/tendermint end  ///////////////////////////
 }
 
 //------------------------------------------------------------------------