diff --git a/consensus/reactor.go b/consensus/reactor.go
index 1ecfcfe38..ca410fa68 100644
--- a/consensus/reactor.go
+++ b/consensus/reactor.go
@@ -107,14 +107,19 @@ func (conR *Reactor) OnStop() {
 func (conR *Reactor) SwitchToConsensus(state sm.State, skipWAL bool) {
 	conR.Logger.Info("SwitchToConsensus")
 
-	// We have no votes, so reconstruct LastCommit from SeenCommit.
-	if state.LastBlockHeight > 0 {
-		conR.conS.reconstructLastCommit(state)
-	}
+	func() {
+		// We need to lock, as we are not entering consensus state from State's `handleMsg` or `handleTimeout`
+		conR.conS.mtx.Lock()
+		defer conR.conS.mtx.Unlock()
+		// We have no votes, so reconstruct LastCommit from SeenCommit
+		if state.LastBlockHeight > 0 {
+			conR.conS.reconstructLastCommit(state)
+		}
 
-	// NOTE: The line below causes broadcastNewRoundStepRoutine() to broadcast a
-	// NewRoundStepMessage.
-	conR.conS.updateToState(state)
+		// NOTE: The line below causes broadcastNewRoundStepRoutine() to broadcast a
+		// NewRoundStepMessage.
+		conR.conS.updateToState(state)
+	}()
 
 	conR.mtx.Lock()
 	conR.waitSync = false