diff --git a/pkg/app_manager.go b/pkg/app_manager.go
index 08c3925..eff74eb 100644
--- a/pkg/app_manager.go
+++ b/pkg/app_manager.go
@@ -214,7 +214,7 @@ func (a *AppManager) ProcessSnapshot(block *types.Block) {
 
 	blocksCount := a.StateManager.GetBlocksCountSinceLatest(a.Config.BlocksWindow)
 
-	neededBlocks := utils.MinInt64(a.Config.BlocksWindow, a.StateManager.GetLastBlockHeight())
+	neededBlocks := utils.MinInt64(a.Config.BlocksWindow, a.StateManager.GetLastBlockHeight()-a.Config.FirstBlock)
 	hasEnoughBlocks := blocksCount >= neededBlocks
 
 	if !hasEnoughBlocks {
diff --git a/pkg/config/chain.go b/pkg/config/chain.go
index 481ba47..5fade49 100644
--- a/pkg/config/chain.go
+++ b/pkg/config/chain.go
@@ -23,6 +23,7 @@ type ChainConfig struct {
 	BlocksWindow       int64           `default:"10000"      toml:"blocks-window"`
 	MinSignedPerWindow float64         `default:"0.05"       toml:"min-signed-per-window"`
 	SnapshotsInterval  int64           `default:"1"          toml:"snapshots-interval"`
+	FirstBlock         int64           `default:"0"          toml:"first-block"`
 	Pagination         ChainPagination `toml:"pagination"`
 	Intervals          IntervalsConfig `toml:"intervals"`
 
diff --git a/pkg/state/manager.go b/pkg/state/manager.go
index 9a9a0c8..d288728 100644
--- a/pkg/state/manager.go
+++ b/pkg/state/manager.go
@@ -140,7 +140,7 @@ func (m *Manager) GetSnapshot() (snapshotPkg.Snapshot, error) {
 	validators := m.state.GetValidators()
 	entries := make(types.Entries, len(validators))
 
-	neededBlocks := utils.MinInt64(m.config.BlocksWindow, m.GetLastBlockHeight())
+	neededBlocks := utils.MinInt64(m.config.BlocksWindow, m.GetLastBlockHeight()-m.config.FirstBlock)
 
 	for _, validator := range validators {
 		// Taking the active status from the last block, as there might be a case
@@ -238,7 +238,7 @@ func (m *Manager) GetBlockTime() time.Duration {
 }
 
 func (m *Manager) GetValidatorMissedBlocks(validator *types.Validator) (types.SignatureInto, error) {
-	blocksToCheck := utils.MinInt64(m.config.BlocksWindow, m.GetLastBlockHeight())
+	blocksToCheck := utils.MinInt64(m.config.BlocksWindow, m.GetLastBlockHeight()-m.config.FirstBlock)
 	return m.state.GetValidatorMissedBlocks(validator, blocksToCheck)
 }