diff --git a/trie/node_enc.go b/trie/node_enc.go
index 7cd421b225..c95587eeab 100644
--- a/trie/node_enc.go
+++ b/trie/node_enc.go
@@ -81,12 +81,6 @@ func (n *extNodeEncoder) encode(w rlp.EncoderBuffer) {
 
 func (n *leafNodeEncoder) encode(w rlp.EncoderBuffer) {
 	offset := w.List()
-
-	// Encode the key to Compact format. The assumption is held
-	// that it's safe to modify the key in place.
-	n.Key = append(n.Key, 16) // termination flag
-	n.Key = hexToCompactInPlace(n.Key)
-
 	w.WriteBytes(n.Key) // Compact format key
 	w.WriteBytes(n.Val) // Value node, must be non-nil
 	w.ListEnd(offset)
diff --git a/trie/stacktrie.go b/trie/stacktrie.go
index 41992b1b7c..2b7366c3c5 100644
--- a/trie/stacktrie.go
+++ b/trie/stacktrie.go
@@ -68,7 +68,7 @@ func (t *StackTrie) grow(key []byte) {
 	if cap(t.kBuf) < 2*len(key) {
 		t.kBuf = make([]byte, 2*len(key))
 	}
-	if cap(t.pBuf) < len(key) {
+	if cap(t.pBuf) < 2*len(key) {
 		t.pBuf = make([]byte, 2*len(key))
 	}
 }
@@ -353,6 +353,7 @@ func (t *StackTrie) hash(st *stNode, path []byte) {
 		}
 		nodes.encode(t.h.encbuf)
 		blob = t.h.encodedBytes()
+
 		for i, child := range st.children {
 			if child == nil {
 				continue
@@ -377,8 +378,9 @@ func (t *StackTrie) hash(st *stNode, path []byte) {
 		st.children[0] = nil
 
 	case leafNode:
+		st.key = append(st.key, byte(16))
 		n := leafNodeEncoder{
-			Key: st.key,
+			Key: hexToCompactInPlace(st.key),
 			Val: st.val,
 		}
 		n.encode(t.h.encbuf)