diff --git a/cli/wallet/wallet.go b/cli/wallet/wallet.go
index 911e9afa9..915321559 100644
--- a/cli/wallet/wallet.go
+++ b/cli/wallet/wallet.go
@@ -13,6 +13,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/native/nativenames"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/address"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/wallet"
@@ -420,8 +421,8 @@ func importDeployed(ctx *cli.Context) error {
 		return cli.NewExitError(fmt.Errorf("can't fetch contract info: %w", err), 1)
 	}
 	md := cs.Manifest.ABI.GetMethod(manifest.MethodVerify, -1)
-	if md == nil {
-		return cli.NewExitError("contract has no `verify` method", 1)
+	if md == nil || md.ReturnType != smartcontract.BoolType {
+		return cli.NewExitError("contract has no `verify` method with boolean return", 1)
 	}
 	acc.Address = address.Uint160ToString(cs.Hash)
 	acc.Contract.Script = cs.NEF.Script
diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index 94052597c..0e4983d4b 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -28,6 +28,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/bigint"
 	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
@@ -1668,7 +1669,7 @@ func (bc *Blockchain) initVerificationVM(ic *interop.Context, hash util.Uint160,
 			return ErrUnknownVerificationContract
 		}
 		md := cs.Manifest.ABI.GetMethod(manifest.MethodVerify, -1)
-		if md == nil {
+		if md == nil || md.ReturnType != smartcontract.BoolType {
 			return ErrInvalidVerificationContract
 		}
 		initMD := cs.Manifest.ABI.GetMethod(manifest.MethodInit, 0)