diff --git a/abci/example/kvstore/kvstore.go b/abci/example/kvstore/kvstore.go
index 6b98d54bb..dab2f0e19 100644
--- a/abci/example/kvstore/kvstore.go
+++ b/abci/example/kvstore/kvstore.go
@@ -290,10 +290,10 @@ func (app *Application) PrepareProposal(req types.RequestPrepareProposal) types.
 func (*Application) ProcessProposal(req types.RequestProcessProposal) types.ResponseProcessProposal {
 	for _, tx := range req.Txs {
 		if len(tx) == 0 {
-			return types.ResponseProcessProposal{Accept: false}
+			return types.ResponseProcessProposal{Status: types.ResponseProcessProposal_REJECT}
 		}
 	}
-	return types.ResponseProcessProposal{Accept: true}
+	return types.ResponseProcessProposal{Status: types.ResponseProcessProposal_ACCEPT}
 }
 
 //---------------------------------------------
diff --git a/abci/types/types.go b/abci/types/types.go
index 4240301b5..eba606b54 100644
--- a/abci/types/types.go
+++ b/abci/types/types.go
@@ -53,6 +53,22 @@ func (r ResponseQuery) IsErr() bool {
 	return r.Code != CodeTypeOK
 }
 
+func (r ResponsePrepareProposal) UnknownModifiedTx() bool {
+	return r.ModifiedTxStatus == ResponsePrepareProposal_UNKNOWN
+}
+
+func (r ResponsePrepareProposal) TxModified() bool {
+	return r.ModifiedTxStatus == ResponsePrepareProposal_MODIFIED
+}
+
+func (r ResponseProcessProposal) IsAccepted() bool {
+	return r.Status == ResponseProcessProposal_ACCEPT
+}
+
+func (r ResponseProcessProposal) IsStatusUnknown() bool {
+	return r.Status == ResponseProcessProposal_ACCEPT
+}
+
 // IsUnknown returns true if Code is Unknown
 func (r ResponseVerifyVoteExtension) IsUnknown() bool {
 	return r.Result == ResponseVerifyVoteExtension_UNKNOWN
diff --git a/internal/consensus/mempool_test.go b/internal/consensus/mempool_test.go
index e527e8598..3c1dc8064 100644
--- a/internal/consensus/mempool_test.go
+++ b/internal/consensus/mempool_test.go
@@ -315,5 +315,5 @@ func (app *CounterApplication) PrepareProposal(
 
 func (app *CounterApplication) ProcessProposal(
 	req abci.RequestProcessProposal) abci.ResponseProcessProposal {
-	return abci.ResponseProcessProposal{Accept: true}
+	return abci.ResponseProcessProposal{Status: abci.ResponseProcessProposal_ACCEPT}
 }
diff --git a/internal/consensus/state_test.go b/internal/consensus/state_test.go
index f008e75d3..4c8886853 100644
--- a/internal/consensus/state_test.go
+++ b/internal/consensus/state_test.go
@@ -1988,7 +1988,7 @@ func TestFinalizeBlockCalled(t *testing.T) {
 			defer cancel()
 
 			m := abcimocks.NewBaseMock()
-			m.On("ProcessProposal", mock.Anything).Return(abcitypes.ResponseProcessProposal{Accept: true})
+			m.On("ProcessProposal", mock.Anything).Return(abcitypes.ResponseProcessProposal{Status: abci.ResponseProcessProposal_ACCEPT})
 			m.On("VerifyVoteExtension", mock.Anything).Return(abcitypes.ResponseVerifyVoteExtension{
 				Result: abcitypes.ResponseVerifyVoteExtension_ACCEPT,
 			})
diff --git a/internal/state/execution.go b/internal/state/execution.go
index 3423b00f6..906a7ec3f 100644
--- a/internal/state/execution.go
+++ b/internal/state/execution.go
@@ -140,8 +140,11 @@ func (blockExec *BlockExecutor) CreateProposalBlock(
 		// purpose for now.
 		panic(err)
 	}
+	if rpp.UnknownModifiedTx() {
+		panic(fmt.Sprintf("PrepareProposal responded with ModifiedTxStatus %s", rpp.ModifiedTxStatus.String()))
+	}
 
-	if !rpp.ModifiedTx {
+	if !rpp.TxModified() {
 		return block, nil
 	}
 	txrSet := types.NewTxRecordSet(rpp.TxRecords)
@@ -181,8 +184,11 @@ func (blockExec *BlockExecutor) ProcessProposal(
 	if err != nil {
 		return false, ErrInvalidBlock(err)
 	}
+	if resp.IsStatusUnknown() {
+		panic(fmt.Sprintf("ProcessProposal responded with status %s", resp.Status.String()))
+	}
 
-	return resp.Accept, nil
+	return resp.IsAccepted(), nil
 }
 
 // ValidateBlock validates the given block against the given state.
diff --git a/internal/state/execution_test.go b/internal/state/execution_test.go
index 3df5afab7..471effa5a 100644
--- a/internal/state/execution_test.go
+++ b/internal/state/execution_test.go
@@ -338,7 +338,7 @@ func TestProcessProposal(t *testing.T) {
 		},
 	}
 
-	app.On("ProcessProposal", mock.Anything).Return(abci.ResponseProcessProposal{Accept: true})
+	app.On("ProcessProposal", mock.Anything).Return(abci.ResponseProcessProposal{Status: abci.ResponseProcessProposal_ACCEPT})
 	acceptBlock, err := blockExec.ProcessProposal(ctx, block1, state)
 	require.NoError(t, err)
 	require.True(t, acceptBlock)
diff --git a/internal/state/helpers_test.go b/internal/state/helpers_test.go
index dffb6f256..1e0187247 100644
--- a/internal/state/helpers_test.go
+++ b/internal/state/helpers_test.go
@@ -320,8 +320,8 @@ func (app *testApp) Query(reqQuery abci.RequestQuery) (resQuery abci.ResponseQue
 func (app *testApp) ProcessProposal(req abci.RequestProcessProposal) abci.ResponseProcessProposal {
 	for _, tx := range req.Txs {
 		if len(tx) == 0 {
-			return abci.ResponseProcessProposal{Accept: false}
+			return abci.ResponseProcessProposal{Status: abci.ResponseProcessProposal_REJECT}
 		}
 	}
-	return abci.ResponseProcessProposal{Accept: true}
+	return abci.ResponseProcessProposal{Status: abci.ResponseProcessProposal_ACCEPT}
 }
diff --git a/test/e2e/app/app.go b/test/e2e/app/app.go
index 4b5a88821..1ed1055ca 100644
--- a/test/e2e/app/app.go
+++ b/test/e2e/app/app.go
@@ -315,10 +315,10 @@ func (app *Application) ProcessProposal(req abci.RequestProcessProposal) abci.Re
 	for _, tx := range req.Txs {
 		_, _, err := parseTx(tx)
 		if err != nil {
-			return abci.ResponseProcessProposal{Accept: false}
+			return abci.ResponseProcessProposal{Status: abci.ResponseProcessProposal_REJECT}
 		}
 	}
-	return abci.ResponseProcessProposal{Accept: true}
+	return abci.ResponseProcessProposal{Status: abci.ResponseProcessProposal_ACCEPT}
 }
 
 func (app *Application) Rollback() error {