diff --git a/neofs/neofs_contract.go b/neofs/neofs_contract.go
index 8d2c54a..50a930b 100644
--- a/neofs/neofs_contract.go
+++ b/neofs/neofs_contract.go
@@ -124,7 +124,7 @@ func _deploy(data interface{}, isUpdate bool) {
 // only by side chain committee.
 func Update(script []byte, manifest []byte, data interface{}) {
 	blockHeight := ledger.CurrentIndex()
-	alphabetKeys := roles.GetDesignatedByRole(roles.NeoFSAlphabet, uint32(blockHeight))
+	alphabetKeys := roles.GetDesignatedByRole(roles.NeoFSAlphabet, uint32(blockHeight+1))
 	alphabetCommittee := common.Multiaddress(alphabetKeys, true)
 
 	common.CheckAlphabetWitness(alphabetCommittee)
diff --git a/processing/processing_contract.go b/processing/processing_contract.go
index fb81a71..f8c149e 100644
--- a/processing/processing_contract.go
+++ b/processing/processing_contract.go
@@ -52,7 +52,7 @@ func _deploy(data interface{}, isUpdate bool) {
 // only by side chain committee.
 func Update(script []byte, manifest []byte, data interface{}) {
 	blockHeight := ledger.CurrentIndex()
-	alphabetKeys := roles.GetDesignatedByRole(roles.NeoFSAlphabet, uint32(blockHeight))
+	alphabetKeys := roles.GetDesignatedByRole(roles.NeoFSAlphabet, uint32(blockHeight+1))
 	alphabetCommittee := common.Multiaddress(alphabetKeys, true)
 
 	if !runtime.CheckWitness(alphabetCommittee) {