diff --git a/blockstore/splitstore/splitstore.go b/blockstore/splitstore/splitstore.go
index 3d7049010..daace6959 100644
--- a/blockstore/splitstore/splitstore.go
+++ b/blockstore/splitstore/splitstore.go
@@ -122,7 +122,6 @@ type SplitStore struct {
 	baseEpoch    abi.ChainEpoch
 	syncGapEpoch abi.ChainEpoch
 	warmupEpoch  abi.ChainEpoch
-	warm         bool
 
 	coldPurgeSize int
 
@@ -364,13 +363,12 @@ func (s *SplitStore) Start(chain ChainAccessor) error {
 	switch err {
 	case nil:
 		s.warmupEpoch = bytesToEpoch(bs)
-		s.warm = true
 
 	case dstore.ErrNotFound:
 		// the hotstore hasn't warmed up, load the genesis into the hotstore
-		err = s.loadGenesisState()
+		err = s.warmup(s.curTs)
 		if err != nil {
-			return xerrors.Errorf("error loading genesis state: %w", err)
+			return xerrors.Errorf("error warming up: %w", err)
 		}
 
 	default:
@@ -449,32 +447,6 @@ func (s *SplitStore) HeadChange(_, apply []*types.TipSet) error {
 		return nil
 	}
 
-	if !s.warm {
-		// splitstore needs to warm up
-		go func() {
-			defer atomic.StoreInt32(&s.compacting, 0)
-
-			log.Info("warming up hotstore")
-			start := time.Now()
-
-			baseTs, err := s.chain.GetTipsetByHeight(context.Background(), s.baseEpoch, curTs, true)
-			if err != nil {
-				log.Errorf("error warming up hotstore: error getting tipset at base epoch: %s", err)
-				return
-			}
-
-			err = s.warmup(baseTs)
-			if err != nil {
-				log.Errorf("error warming up hotstore: %s", err)
-				return
-			}
-
-			log.Infow("warm up done", "took", time.Since(start))
-		}()
-
-		return nil
-	}
-
 	if epoch-s.baseEpoch > CompactionThreshold {
 		// it's time to compact
 		go func() {
@@ -495,6 +467,41 @@ func (s *SplitStore) HeadChange(_, apply []*types.TipSet) error {
 	return nil
 }
 
+func (s *SplitStore) warmup(curTs *types.TipSet) error {
+	err := s.loadGenesisState()
+	if err != nil {
+		return xerrors.Errorf("error loading genesis state: %w")
+	}
+
+	if !atomic.CompareAndSwapInt32(&s.compacting, 0, 1) {
+		return xerrors.Errorf("error locking compaction")
+	}
+
+	go func() {
+		defer atomic.StoreInt32(&s.compacting, 0)
+
+		log.Info("warming up hotstore")
+		start := time.Now()
+
+		err = s.doWarmup(curTs)
+		if err != nil {
+			log.Errorf("error warming up hotstore: %s", err)
+			return
+		}
+
+		log.Infow("warm up done", "took", time.Since(start))
+	}()
+
+	// save the warmup epoch
+	s.warmupEpoch = curTs.Height()
+	err = s.ds.Put(warmupEpochKey, epochToBytes(s.warmupEpoch))
+	if err != nil {
+		return xerrors.Errorf("error saving warm up epoch: %w")
+	}
+
+	return nil
+}
+
 func (s *SplitStore) loadGenesisState() error {
 	// makes sure the genesis and its state root are hot
 	gb, err := s.chain.GetGenesis()
@@ -554,7 +561,7 @@ func (s *SplitStore) loadGenesisState() error {
 	return nil
 }
 
-func (s *SplitStore) warmup(curTs *types.TipSet) error {
+func (s *SplitStore) doWarmup(curTs *types.TipSet) error {
 	epoch := curTs.Height()
 
 	batchHot := make([]blocks.Block, 0, batchSize)
@@ -629,14 +636,6 @@ func (s *SplitStore) warmup(curTs *types.TipSet) error {
 		s.markSetSize = count + count>>2 // overestimate a bit
 	}
 
-	// save the warmup epoch
-	s.warm = true
-	s.warmupEpoch = epoch
-	err = s.ds.Put(warmupEpochKey, epochToBytes(epoch))
-	if err != nil {
-		log.Warnf("error saving warmup epoch: %s", err)
-	}
-
 	err = s.ds.Put(markSetSizeKey, int64ToBytes(s.markSetSize))
 	if err != nil {
 		log.Warnf("error saving mark set size: %s", err)