diff --git a/orderedmap.go b/orderedmap.go
index 9c013ec..816fcc6 100644
--- a/orderedmap.go
+++ b/orderedmap.go
@@ -1,6 +1,9 @@
 package orderedmap
 
+import "sync"
+
 type OrderedMap struct {
+	sync.RWMutex
 	kv map[interface{}]*Element
 	ll list
 }
@@ -22,6 +25,9 @@ func NewOrderedMapWithCapacity(capacity int) *OrderedMap {
 // Get returns the value for a key. If the key does not exist, the second return
 // parameter will be false and the value will be nil.
 func (m *OrderedMap) Get(key interface{}) (interface{}, bool) {
+	m.RLock()
+	defer m.RUnlock()
+
 	element, ok := m.kv[key]
 	if ok {
 		return element.Value, true
@@ -34,6 +40,9 @@ func (m *OrderedMap) Get(key interface{}) (interface{}, bool) {
 // will be returned. The returned value will be false if the value was replaced
 // (even if the value was the same).
 func (m *OrderedMap) Set(key, value interface{}) bool {
+	m.Lock()
+	defer m.Unlock()
+
 	_, alreadyExist := m.kv[key]
 	if alreadyExist {
 		m.kv[key].Value = value
@@ -48,6 +57,9 @@ func (m *OrderedMap) Set(key, value interface{}) bool {
 // GetOrDefault returns the value for a key. If the key does not exist, returns
 // the default value instead.
 func (m *OrderedMap) GetOrDefault(key, defaultValue interface{}) interface{} {
+	m.RLock()
+	defer m.RUnlock()
+
 	if element, ok := m.kv[key]; ok {
 		return element.Value
 	}
@@ -58,6 +70,9 @@ func (m *OrderedMap) GetOrDefault(key, defaultValue interface{}) interface{} {
 // GetElement returns the element for a key. If the key does not exist, the
 // pointer will be nil.
 func (m *OrderedMap) GetElement(key interface{}) *Element {
+	m.RLock()
+	defer m.RUnlock()
+
 	element, ok := m.kv[key]
 	if ok {
 		return element
@@ -68,6 +83,9 @@ func (m *OrderedMap) GetElement(key interface{}) *Element {
 
 // Len returns the number of elements in the map.
 func (m *OrderedMap) Len() int {
+	m.RLock()
+	defer m.RUnlock()
+
 	return len(m.kv)
 }
 
@@ -75,6 +93,9 @@ func (m *OrderedMap) Len() int {
 // replaced it will retain the same position. To ensure most recently set keys
 // are always at the end you must always Delete before Set.
 func (m *OrderedMap) Keys() (keys []interface{}) {
+	m.RLock()
+	defer m.RUnlock()
+
 	keys = make([]interface{}, 0, m.Len())
 	for el := m.Front(); el != nil; el = el.Next() {
 		keys = append(keys, el.Key)
@@ -85,6 +106,9 @@ func (m *OrderedMap) Keys() (keys []interface{}) {
 // Delete will remove a key from the map. It will return true if the key was
 // removed (the key did exist).
 func (m *OrderedMap) Delete(key interface{}) (didDelete bool) {
+	m.Lock()
+	defer m.Unlock()
+
 	element, ok := m.kv[key]
 	if ok {
 		m.ll.Remove(element)
@@ -97,18 +121,27 @@ func (m *OrderedMap) Delete(key interface{}) (didDelete bool) {
 // Front will return the element that is the first (oldest Set element). If
 // there are no elements this will return nil.
 func (m *OrderedMap) Front() *Element {
+	m.RLock()
+	defer m.RUnlock()
+
 	return m.ll.Front()
 }
 
 // Back will return the element that is the last (most recent Set element). If
 // there are no elements this will return nil.
 func (m *OrderedMap) Back() *Element {
+	m.RLock()
+	defer m.RUnlock()
+
 	return m.ll.Back()
 }
 
 // Copy returns a new OrderedMap with the same elements.
 // Using Copy while there are concurrent writes may mangle the result.
 func (m *OrderedMap) Copy() *OrderedMap {
+	m.RLock()
+	defer m.RUnlock()
+
 	m2 := NewOrderedMapWithCapacity(m.Len())
 
 	for el := m.Front(); el != nil; el = el.Next() {
@@ -120,6 +153,9 @@ func (m *OrderedMap) Copy() *OrderedMap {
 
 // Has checks if a key exists in the map.
 func (m *OrderedMap) Has(key interface{}) bool {
+	m.RLock()
+	defer m.RUnlock()
+
 	_, exists := m.kv[key]
 	return exists
 }
diff --git a/orderedmap_test.go b/orderedmap_test.go
index 153f60c..e7f17c0 100644
--- a/orderedmap_test.go
+++ b/orderedmap_test.go
@@ -3,6 +3,7 @@ package orderedmap_test
 import (
 	"fmt"
 	"strconv"
+	"sync"
 	"testing"
 
 	"github.com/elliotchance/orderedmap"
@@ -1168,6 +1169,31 @@ func BenchmarkBigOrderedMapString_Has(b *testing.B) {
 	benchmarkBigOrderedMapString_Has()(b)
 }
 
+func TestThreadSafe(t *testing.T) {
+	m := orderedmap.NewOrderedMap()
+	wg := &sync.WaitGroup{}
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 1000000; i++ {
+			_ = m.Set(i, i)
+		}
+	}()
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 1000000; i++ {
+			_ = m.Set(i, i)
+		}
+	}()
+	wg.Wait()
+	for i := 0; i < 1000000; i++ {
+		if !m.Has(i) {
+			t.Fail()
+		}
+	}
+}
+
 func BenchmarkAll(b *testing.B) {
 	b.Run("BenchmarkOrderedMap_Keys", BenchmarkOrderedMap_Keys)