diff --git a/blockstore/splitstore/markset_map.go b/blockstore/splitstore/markset_map.go
index 52efcb8a48..922800eafa 100644
--- a/blockstore/splitstore/markset_map.go
+++ b/blockstore/splitstore/markset_map.go
@@ -42,6 +42,11 @@ func NewMapMarkSetEnv(path string) (*MapMarkSetEnv, error) {
 
 func (e *MapMarkSetEnv) New(name string, sizeHint int64) (MarkSet, error) {
 	path := filepath.Join(e.path, name)
+	// Limit map size to 1k if sizeHint exceeds this value
+	// This prevents accidental hanging when sizeHint is too large
+	if sizeHint > 1000 {
+		sizeHint = 1000
+	}
 	return &MapMarkSet{
 		set:  make(map[string]struct{}, sizeHint),
 		path: path,
diff --git a/blockstore/splitstore/splitstore_warmup.go b/blockstore/splitstore/splitstore_warmup.go
index e57ea25a52..1410751040 100644
--- a/blockstore/splitstore/splitstore_warmup.go
+++ b/blockstore/splitstore/splitstore_warmup.go
@@ -59,10 +59,7 @@ func (s *SplitStore) doWarmup2(curTs *types.TipSet) error {
 	log.Infow("warmup starting")
 
 	epoch := curTs.Height()
-	count := new(int64)
-	// Empirically taken from December 2024
-	*count = MarkSetEstimate
-	s.markSetSize = *count + *count>>2 // overestimate a bit
+	s.markSetSize = MarkSetEstimate
 	err := s.ds.Put(s.ctx, markSetSizeKey, int64ToBytes(s.markSetSize))
 	if err != nil {
 		log.Warnf("error saving mark set size: %s", err)