diff --git a/proofs.go b/proofs.go
index 6a09fe9..be33a8f 100644
--- a/proofs.go
+++ b/proofs.go
@@ -346,7 +346,7 @@ func VerifyClosestProof(proof *SparseMerkleClosestProof, root []byte, spec *Trie
 	// will invalidate the proof.
 	nilSpec := &TrieSpec{
 		th:      spec.th,
-		ph:      newNilPathHasher(spec.ph.PathSize()),
+		ph:      NewNilPathHasher(spec.ph.PathSize()),
 		vh:      spec.vh,
 		sumTrie: spec.sumTrie,
 	}
diff --git a/types.go b/types.go
index f860bba..61b0638 100644
--- a/types.go
+++ b/types.go
@@ -87,11 +87,16 @@ type TrieSpec struct {
 	sumTrie bool
 }
 
-func NewTrieSpec(hasher hash.Hash, sumTrie bool) TrieSpec {
+func NewTrieSpec(hasher hash.Hash, sumTrie bool, opts ...Option) TrieSpec {
 	spec := TrieSpec{th: *newTrieHasher(hasher)}
 	spec.ph = &pathHasher{spec.th}
 	spec.vh = &valueHasher{spec.th}
 	spec.sumTrie = sumTrie
+
+	for _, opt := range opts {
+		opt(&spec)
+	}
+
 	return spec
 }
 
diff --git a/utils.go b/utils.go
index cc5bca8..64e98cb 100644
--- a/utils.go
+++ b/utils.go
@@ -10,8 +10,8 @@ type nilPathHasher struct {
 
 func (n *nilPathHasher) Path(key []byte) []byte { return key[:n.hashSize] }
 func (n *nilPathHasher) PathSize() int          { return n.hashSize }
-
-func newNilPathHasher(hashSize int) PathHasher {
+	
+func NewNilPathHasher(hashSize int) PathHasher {
 	return &nilPathHasher{hashSize: hashSize}
 }