diff --git a/pkg/core/block/block.go b/pkg/core/block/block.go
index 32215098b..3e451258f 100644
--- a/pkg/core/block/block.go
+++ b/pkg/core/block/block.go
@@ -229,6 +229,7 @@ func (b *Block) ToStackItem() stackitem.Item {
 		stackitem.NewBigInteger(big.NewInt(int64(b.Timestamp))),
 		stackitem.NewBigInteger(new(big.Int).SetUint64(b.Nonce)),
 		stackitem.NewBigInteger(big.NewInt(int64(b.Index))),
+		stackitem.NewBigInteger(big.NewInt(int64(b.PrimaryIndex))),
 		stackitem.NewByteArray(b.NextConsensus.BytesBE()),
 		stackitem.NewBigInteger(big.NewInt(int64(len(b.Transactions)))),
 	}
diff --git a/pkg/core/native/native_test/ledger_test.go b/pkg/core/native/native_test/ledger_test.go
index a7d878aef..308120b21 100644
--- a/pkg/core/native/native_test/ledger_test.go
+++ b/pkg/core/native/native_test/ledger_test.go
@@ -159,6 +159,7 @@ func TestLedger_GetBlock(t *testing.T) {
 		stackitem.NewBigInteger(big.NewInt(int64(b.Timestamp))),
 		stackitem.NewBigInteger(big.NewInt(int64(b.Nonce))),
 		stackitem.NewBigInteger(big.NewInt(int64(b.Index))),
+		stackitem.NewBigInteger(big.NewInt(int64(b.PrimaryIndex))),
 		stackitem.NewByteArray(b.NextConsensus.BytesBE()),
 		stackitem.NewBigInteger(big.NewInt(int64(len(b.Transactions)))),
 	}
diff --git a/pkg/interop/native/ledger/block.go b/pkg/interop/native/ledger/block.go
index 0164803cb..58c88521a 100644
--- a/pkg/interop/native/ledger/block.go
+++ b/pkg/interop/native/ledger/block.go
@@ -23,6 +23,8 @@ type Block struct {
 	Nonce int
 	// Index represents the height of the block.
 	Index int
+	// PrimaryIndex represents the index of the primary node that created this block.
+	PrimaryIndex int
 	// NextConsensus represents the contract address of the next miner (160 bit BE
 	// value in a 20 byte slice).
 	NextConsensus interop.Hash160
@@ -43,6 +45,7 @@ type BlockSR struct {
 	Timestamp          int
 	Nonce              int
 	Index              int
+	PrimaryIndex       int
 	NextConsensus      interop.Hash160
 	TransactionsLength int
 	// PrevStateRoot is a hash of the previous block's state root.