diff --git a/simapp/abci.go b/simapp/abci.go
new file mode 100644
index 000000000000..7848d254d50f
--- /dev/null
+++ b/simapp/abci.go
@@ -0,0 +1,84 @@
+package simapp
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/json"
+	"fmt"
+
+	abci "github.com/cometbft/cometbft/abci/types"
+
+	"github.com/cosmos/cosmos-sdk/baseapp"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+type (
+	// VoteExtensionHandler defines a dummy vote extension handler for SimApp.
+	//
+	// NOTE: This implementation is solely used for testing purposes. DO NOT use
+	// in a production application!
+	VoteExtensionHandler struct{}
+
+	// VoteExtension defines the structure used to create a dummy vote extension.
+	VoteExtension struct {
+		Hash   []byte
+		Height int64
+		Data   []byte
+	}
+)
+
+func NewVoteExtensionHandler() *VoteExtensionHandler {
+	return &VoteExtensionHandler{}
+}
+
+func (h *VoteExtensionHandler) SetHandlers(bApp *baseapp.BaseApp) {
+	bApp.SetExtendVoteHandler(h.ExtendVote())
+	bApp.SetVerifyVoteExtensionHandler(h.VerifyVoteExtension())
+}
+
+func (h *VoteExtensionHandler) ExtendVote() sdk.ExtendVoteHandler {
+	return func(_ sdk.Context, req *abci.RequestExtendVote) (*abci.ResponseExtendVote, error) {
+		buf := make([]byte, 1024)
+
+		_, err := rand.Read(buf)
+		if err != nil {
+			return nil, fmt.Errorf("failed to generate random vote extension data: %w", err)
+		}
+
+		ve := VoteExtension{
+			Hash:   req.Hash,
+			Height: req.Height,
+			Data:   buf,
+		}
+
+		bz, err := json.Marshal(ve)
+		if err != nil {
+			return nil, fmt.Errorf("failed to encode vote extension: %w", err)
+		}
+
+		return &abci.ResponseExtendVote{VoteExtension: bz}, nil
+	}
+}
+
+func (h *VoteExtensionHandler) VerifyVoteExtension() sdk.VerifyVoteExtensionHandler {
+	return func(ctx sdk.Context, req *abci.RequestVerifyVoteExtension) (*abci.ResponseVerifyVoteExtension, error) {
+		var ve VoteExtension
+
+		if err := json.Unmarshal(req.VoteExtension, &ve); err != nil {
+			return &abci.ResponseVerifyVoteExtension{Status: abci.ResponseVerifyVoteExtension_REJECT}, nil
+		}
+
+		switch {
+		case req.Height != ve.Height:
+			return &abci.ResponseVerifyVoteExtension{Status: abci.ResponseVerifyVoteExtension_REJECT}, nil
+
+		case !bytes.Equal(req.Hash, ve.Hash):
+			return &abci.ResponseVerifyVoteExtension{Status: abci.ResponseVerifyVoteExtension_REJECT}, nil
+
+		case len(ve.Data) != 1024:
+			return &abci.ResponseVerifyVoteExtension{Status: abci.ResponseVerifyVoteExtension_REJECT}, nil
+		}
+
+		return &abci.ResponseVerifyVoteExtension{Status: abci.ResponseVerifyVoteExtension_ACCEPT}, nil
+	}
+}
diff --git a/simapp/app.go b/simapp/app.go
index 7e4681399232..7f8d69385a71 100644
--- a/simapp/app.go
+++ b/simapp/app.go
@@ -9,25 +9,15 @@ import (
 	"os"
 	"path/filepath"
 
-	"cosmossdk.io/log"
-	"cosmossdk.io/x/tx/signing"
-
 	autocliv1 "cosmossdk.io/api/cosmos/autocli/v1"
 	reflectionv1 "cosmossdk.io/api/cosmos/reflection/v1"
 	"cosmossdk.io/client/v2/autocli"
 	"cosmossdk.io/core/appmodule"
-
-	"github.com/cosmos/cosmos-sdk/codec/address"
-
-	authcodec "github.com/cosmos/cosmos-sdk/x/auth/codec"
-	"github.com/cosmos/cosmos-sdk/x/auth/tx"
-
-	abci "github.com/cometbft/cometbft/abci/types"
-	dbm "github.com/cosmos/cosmos-db"
-	"github.com/cosmos/gogoproto/proto"
-	"github.com/spf13/cast"
-
+	"cosmossdk.io/log"
 	storetypes "cosmossdk.io/store/types"
+	"cosmossdk.io/x/circuit"
+	circuitkeeper "cosmossdk.io/x/circuit/keeper"
+	circuittypes "cosmossdk.io/x/circuit/types"
 	"cosmossdk.io/x/evidence"
 	evidencekeeper "cosmossdk.io/x/evidence/keeper"
 	evidencetypes "cosmossdk.io/x/evidence/types"
@@ -37,20 +27,19 @@ import (
 	"cosmossdk.io/x/nft"
 	nftkeeper "cosmossdk.io/x/nft/keeper"
 	nftmodule "cosmossdk.io/x/nft/module"
+	"cosmossdk.io/x/tx/signing"
 	"cosmossdk.io/x/upgrade"
 	upgradekeeper "cosmossdk.io/x/upgrade/keeper"
 	upgradetypes "cosmossdk.io/x/upgrade/types"
-
-	"cosmossdk.io/x/circuit"
-	circuitkeeper "cosmossdk.io/x/circuit/keeper"
-	circuittypes "cosmossdk.io/x/circuit/types"
-
+	abci "github.com/cometbft/cometbft/abci/types"
+	dbm "github.com/cosmos/cosmos-db"
 	"github.com/cosmos/cosmos-sdk/baseapp"
 	"github.com/cosmos/cosmos-sdk/client"
 	"github.com/cosmos/cosmos-sdk/client/flags"
 	"github.com/cosmos/cosmos-sdk/client/grpc/cmtservice"
 	nodeservice "github.com/cosmos/cosmos-sdk/client/grpc/node"
 	"github.com/cosmos/cosmos-sdk/codec"
+	"github.com/cosmos/cosmos-sdk/codec/address"
 	"github.com/cosmos/cosmos-sdk/codec/types"
 	"github.com/cosmos/cosmos-sdk/runtime"
 	runtimeservices "github.com/cosmos/cosmos-sdk/runtime/services"
@@ -66,9 +55,11 @@ import (
 	"github.com/cosmos/cosmos-sdk/version"
 	"github.com/cosmos/cosmos-sdk/x/auth"
 	"github.com/cosmos/cosmos-sdk/x/auth/ante"
+	authcodec "github.com/cosmos/cosmos-sdk/x/auth/codec"
 	authkeeper "github.com/cosmos/cosmos-sdk/x/auth/keeper"
 	"github.com/cosmos/cosmos-sdk/x/auth/posthandler"
 	authsims "github.com/cosmos/cosmos-sdk/x/auth/simulation"
+	"github.com/cosmos/cosmos-sdk/x/auth/tx"
 	authtx "github.com/cosmos/cosmos-sdk/x/auth/tx"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
 	"github.com/cosmos/cosmos-sdk/x/auth/vesting"
@@ -112,6 +103,8 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/staking"
 	stakingkeeper "github.com/cosmos/cosmos-sdk/x/staking/keeper"
 	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
+	"github.com/cosmos/gogoproto/proto"
+	"github.com/spf13/cast"
 )
 
 const appName = "SimApp"
@@ -273,6 +266,13 @@ func NewSimApp(
 	// }
 	// baseAppOptions = append(baseAppOptions, prepareOpt)
 
+	// create and set dummy vote extension handler
+	voteExtOp := func(bApp *baseapp.BaseApp) {
+		voteExtHandler := NewVoteExtensionHandler()
+		voteExtHandler.SetHandlers(bApp)
+	}
+	baseAppOptions = append(baseAppOptions, voteExtOp)
+
 	bApp := baseapp.NewBaseApp(appName, logger, db, txConfig.TxDecoder(), baseAppOptions...)
 	bApp.SetCommitMultiStoreTracer(traceStore)
 	bApp.SetVersion(version.Version)
diff --git a/simapp/app_v2.go b/simapp/app_v2.go
index 7ec1f3732449..936458c86512 100644
--- a/simapp/app_v2.go
+++ b/simapp/app_v2.go
@@ -198,6 +198,13 @@ func NewSimApp(
 	// }
 	// baseAppOptions = append(baseAppOptions, prepareOpt)
 
+	// create and set dummy vote extension handler
+	voteExtOp := func(bApp *baseapp.BaseApp) {
+		voteExtHandler := NewVoteExtensionHandler()
+		voteExtHandler.SetHandlers(bApp)
+	}
+	baseAppOptions = append(baseAppOptions, voteExtOp)
+
 	app.App = appBuilder.Build(db, traceStore, baseAppOptions...)
 
 	// register streaming services