diff --git a/lib/blocktree/errors.go b/lib/blocktree/errors.go
index 5af63f34b1..90e66c0744 100644
--- a/lib/blocktree/errors.go
+++ b/lib/blocktree/errors.go
@@ -45,5 +45,7 @@ var (
 	// ErrNoCommonAncestor is returned when a common ancestor cannot be found between two nodes
 	ErrNoCommonAncestor = errors.New("no common ancestor between two nodes")
 
+	ErrNotADescendant = errors.New("not a descendant")
+
 	errUnexpectedNumber = errors.New("block number is not parent number + 1")
 )
diff --git a/lib/grandpa/grandpa.go b/lib/grandpa/grandpa.go
index c9747e81d6..30b09f7716 100644
--- a/lib/grandpa/grandpa.go
+++ b/lib/grandpa/grandpa.go
@@ -678,13 +678,43 @@ func (s *Service) deleteVote(key ed25519.PublicKeyBytes, stage Subround) {
 	}
 }
 
-// determinePreVote determines what block is our pre-voted block for the current round
-func (s *Service) determinePreVote() (*Vote, error) {
-	var vote *Vote
+func (s *Service) determineBestHeaderToVote(bestBlockHeader,
+	latestFinalizedHeader *types.Header) (vote *types.GrandpaVote, err error) {
+	genesisHash := s.blockState.GenesisHash()
+
+	bestBlockHash := bestBlockHeader.Hash()
+	finalizedHash := latestFinalizedHeader.Hash()
+
+	isGenesisHash := genesisHash.Equal(bestBlockHash)
+	isFinalizedHash := finalizedHash.Equal(bestBlockHash)
+
+	if isGenesisHash || isFinalizedHash {
+		return NewVoteFromHeader(bestBlockHeader), nil
+	}
+
+	isDescendant, err := s.blockState.IsDescendantOf(finalizedHash, bestBlockHash)
+	if err != nil {
+		return nil, fmt.Errorf("determining ancestry: %w", err)
+	}
+
+	if !isDescendant {
+		return nil, fmt.Errorf("%w: %s of %s",
+			blocktree.ErrNotADescendant, bestBlockHash.Short(), finalizedHash.Short())
+	}
 
+	return NewVoteFromHeader(bestBlockHeader), nil
+}
+
+// determinePreVote determines what block is our pre-voted block for the current round
+func (s *Service) determinePreVote() (vote *Vote, err error) {
 	bestBlockHeader, err := s.blockState.BestBlockHeader()
 	if err != nil {
-		return nil, fmt.Errorf("cannot get best block header: %w", err)
+		return nil, fmt.Errorf("getting best block: %w", err)
+	}
+
+	vote, err = s.determineBestHeaderToVote(bestBlockHeader, s.head)
+	if err != nil {
+		return nil, fmt.Errorf("determining best block header to vote: %w", err)
 	}
 
 	// if we receive a vote message from the primary with a
@@ -695,11 +725,11 @@ func (s *Service) determinePreVote() (*Vote, error) {
 	prm, has := s.loadVote(primary.PublicKeyBytes(), prevote)
 	if has && prm.Vote.Number >= uint32(s.head.Number) {
 		vote = &prm.Vote
-	} else {
-		vote = NewVoteFromHeader(bestBlockHeader)
 	}
 
-	nextChange, err := s.grandpaState.NextGrandpaAuthorityChange(bestBlockHeader.Hash(), bestBlockHeader.Number)
+	nextChange, err := s.grandpaState.NextGrandpaAuthorityChange(
+		vote.Hash, uint(vote.Number))
+
 	if errors.Is(err, state.ErrNoNextAuthorityChange) {
 		return vote, nil
 	} else if err != nil {
@@ -709,7 +739,7 @@ func (s *Service) determinePreVote() (*Vote, error) {
 	if uint(vote.Number) > nextChange {
 		header, err := s.blockState.GetHeaderByNumber(nextChange)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("getting header by number: %w", err)
 		}
 		vote = NewVoteFromHeader(header)
 	}
@@ -961,7 +991,8 @@ func (s *Service) getPreVotedBlock() (Vote, error) {
 
 	// if there are multiple, find the one with the highest number and return it
 	highest := Vote{
-		Number: uint32(0),
+		Hash:   s.head.Hash(),
+		Number: uint32(s.head.Number),
 	}
 
 	for h, n := range blocks {
@@ -1005,7 +1036,8 @@ func (s *Service) getGrandpaGHOST() (Vote, error) {
 
 	// if there are multiple, find the one with the highest number and return it
 	highest := Vote{
-		Number: uint32(0),
+		Hash:   s.head.Hash(),
+		Number: uint32(s.head.Number),
 	}
 
 	for h, n := range blocks {
diff --git a/lib/grandpa/grandpa_test.go b/lib/grandpa/grandpa_test.go
index dda0511f9d..7c9daffcfd 100644
--- a/lib/grandpa/grandpa_test.go
+++ b/lib/grandpa/grandpa_test.go
@@ -966,6 +966,7 @@ func TestDeterminePreVote_NoPrimaryPreVote(t *testing.T) {
 
 	header, err := st.Block.BestBlockHeader()
 	require.NoError(t, err)
+
 	require.Equal(t, header.Hash(), pv.Hash)
 }
 
diff --git a/lib/grandpa/message.go b/lib/grandpa/message.go
index 9ab086d67d..3129ed8d61 100644
--- a/lib/grandpa/message.go
+++ b/lib/grandpa/message.go
@@ -56,6 +56,10 @@ type VoteMessage struct {
 	Message SignedMessage
 }
 
+func (v VoteMessage) String() string {
+	return fmt.Sprintf("round=%d, setID=%d, message=%s", v.Round, v.SetID, v.Message)
+}
+
 // Index Returns VDT index
 func (VoteMessage) Index() uint { return 0 }
 
diff --git a/lib/grandpa/message_handler.go b/lib/grandpa/message_handler.go
index fef28cccf5..34b09694cb 100644
--- a/lib/grandpa/message_handler.go
+++ b/lib/grandpa/message_handler.go
@@ -328,7 +328,7 @@ func (h *MessageHandler) verifyCommitMessageJustification(fm *CommitMessage) err
 		return fmt.Errorf("cannot verify ancestry of highest finalised block: %w", err)
 	}
 	if !isDescendant {
-		return errVoteBlockMismatch
+		return fmt.Errorf("%w", errVoteBlockMismatch)
 	}
 
 	eqvVoters := getEquivocatoryVoters(fm.AuthData)
diff --git a/lib/grandpa/round_test.go b/lib/grandpa/round_test.go
index fd9729e602..4597b059a0 100644
--- a/lib/grandpa/round_test.go
+++ b/lib/grandpa/round_test.go
@@ -4,7 +4,6 @@
 package grandpa
 
 import (
-	//"fmt"
 	"math/rand"
 	"sync"
 	"testing"