diff --git a/types/event_bus.go b/types/event_bus.go
index dfe3a0664..8cfe1ea54 100644
--- a/types/event_bus.go
+++ b/types/event_bus.go
@@ -221,10 +221,6 @@ func (b *EventBus) PublishEventPolka(data EventDataRoundState) error {
 	return b.Publish(EventPolkaValue, data)
 }
 
-func (b *EventBus) PublishEventUnlock(data EventDataRoundState) error {
-	return b.Publish(EventUnlockValue, data)
-}
-
 func (b *EventBus) PublishEventRelock(data EventDataRoundState) error {
 	return b.Publish(EventRelockValue, data)
 }
@@ -301,10 +297,6 @@ func (NopEventBus) PublishEventPolka(data EventDataRoundState) error {
 	return nil
 }
 
-func (NopEventBus) PublishEventUnlock(data EventDataRoundState) error {
-	return nil
-}
-
 func (NopEventBus) PublishEventRelock(data EventDataRoundState) error {
 	return nil
 }
diff --git a/types/events.go b/types/events.go
index 46f150abd..ad604befb 100644
--- a/types/events.go
+++ b/types/events.go
@@ -38,7 +38,6 @@ const (
 	EventStateSyncStatusValue = "StateSyncStatus"
 	EventTimeoutProposeValue  = "TimeoutPropose"
 	EventTimeoutWaitValue     = "TimeoutWait"
-	EventUnlockValue          = "Unlock"
 	EventValidBlockValue      = "ValidBlock"
 	EventVoteValue            = "Vote"
 )
@@ -223,7 +222,6 @@ var (
 	EventQueryTimeoutPropose      = QueryForEvent(EventTimeoutProposeValue)
 	EventQueryTimeoutWait         = QueryForEvent(EventTimeoutWaitValue)
 	EventQueryTx                  = QueryForEvent(EventTxValue)
-	EventQueryUnlock              = QueryForEvent(EventUnlockValue)
 	EventQueryValidatorSetUpdates = QueryForEvent(EventValidatorSetUpdatesValue)
 	EventQueryValidBlock          = QueryForEvent(EventValidBlockValue)
 	EventQueryVote                = QueryForEvent(EventVoteValue)