diff --git a/pkg/core/stateroot/store.go b/pkg/core/stateroot/store.go
index ff3b1a6cb..9efcf7c5f 100644
--- a/pkg/core/stateroot/store.go
+++ b/pkg/core/stateroot/store.go
@@ -2,12 +2,20 @@ package stateroot
 
 import (
 	"encoding/binary"
+	"errors"
+	"fmt"
 
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/storage"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 )
 
+var (
+	// ErrStateMismatch means that local state root doesn't match the one
+	// signed by state validators.
+	ErrStateMismatch = errors.New("stateroot mismatch")
+)
+
 const (
 	prefixGC        = 0x01
 	prefixLocal     = 0x02
@@ -60,6 +68,9 @@ func (s *Module) AddStateRoot(sr *state.MPTRoot) error {
 	if err != nil {
 		return err
 	}
+	if !local.Root.Equals(sr.Root) {
+		return fmt.Errorf("%w at block %d: %v vs %v", ErrStateMismatch, sr.Index, local.Root, sr.Root)
+	}
 	if len(local.Witness) != 0 {
 		return nil
 	}