diff --git a/internal/stack/stack.go b/internal/stack/stack.go
new file mode 100644
index 00000000..4481da02
--- /dev/null
+++ b/internal/stack/stack.go
@@ -0,0 +1,40 @@
+// Copyright 2017 The go-interpreter Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package stack implements a growable uint64 stack
+package stack
+
+type Stack struct {
+	slice []uint64
+}
+
+func (s *Stack) Push(b uint64) {
+	s.slice = append(s.slice, b)
+}
+
+func (s *Stack) Pop() uint64 {
+	v := s.Top()
+	s.slice = s.slice[:len(s.slice)-1]
+	return v
+}
+
+func (s *Stack) SetTop(v uint64) {
+	s.slice[len(s.slice)-1] = v
+}
+
+func (s *Stack) Top() uint64 {
+	return s.slice[len(s.slice)-1]
+}
+
+func (s *Stack) Get(i int) uint64 {
+	return s.slice[i]
+}
+
+func (s *Stack) Set(i int, v uint64) {
+	s.slice[i] = v
+}
+
+func (s *Stack) Len() int {
+	return len(s.slice)
+}