diff --git a/trie/bintrie/stem_node.go b/trie/bintrie/stem_node.go
index 9f1ac6d2e0..e44d25638f 100644
--- a/trie/bintrie/stem_node.go
+++ b/trie/bintrie/stem_node.go
@@ -97,6 +97,7 @@ func (sn *StemNode) ensureWritable() {
 
 // setValue sets or inserts a value at the given suffix.
 func (sn *StemNode) setValue(suffix byte, value []byte) {
+	sn.ensureWritable()
 	idx := int(suffix)
 	pos := sn.posInData(suffix)
 	if pos >= 0 {
diff --git a/trie/bintrie/store_ops.go b/trie/bintrie/store_ops.go
index 83885feacc..6bb966a074 100644
--- a/trie/bintrie/store_ops.go
+++ b/trie/bintrie/store_ops.go
@@ -192,7 +192,6 @@ func (s *NodeStore) InsertSingle(stem []byte, suffix byte, value []byte, resolve
 	if s.root.Kind() == KindStem {
 		sn := s.getStem(s.root.Index())
 		if sn.Stem == [StemSize]byte(stem[:StemSize]) {
-			sn.ensureWritable()
 			sn.setValue(suffix, value)
 			sn.mustRecompute = true
 			return nil
@@ -235,7 +234,6 @@ func (s *NodeStore) insertSingleInternal(stem []byte, suffix byte, value []byte,
 		case KindStem:
 			sn := s.getStem(cur.Index())
 			if sn.Stem == [StemSize]byte(stem[:StemSize]) {
-				sn.ensureWritable()
 				sn.setValue(suffix, value)
 				sn.mustRecompute = true
 				return nil
@@ -432,7 +430,6 @@ func (s *NodeStore) insertValuesAtStem(ref NodeRef, stem []byte, values [][]byte
 		sn := s.getStem(ref.Index())
 		if sn.Stem == [StemSize]byte(stem[:StemSize]) {
 			// Same stem — merge values
-			sn.ensureWritable()
 			for i, v := range values {
 				if v != nil {
 					sn.setValue(byte(i), v)