diff --git a/CHANGELOG.md b/CHANGELOG.md
index 886231c8d..6a1609a21 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,10 +1,15 @@
 # Changelog
 
+## v1.7.1 (25 Sep 2017)
+
+Bugfixes:
+* [#504][]: Store strings when using AddByteString with the map encoder.
+
 ## v1.7.0 (21 Sep 2017)
 
 Enhancements:
 
-* [#439][]: Add `NewStdLogAt`, which extends `NewStdLog` by allowing the user
+* [#487][]: Add `NewStdLogAt`, which extends `NewStdLog` by allowing the user
   to specify the level of the logged messages.
 
 ## v1.6.0 (30 Aug 2017)
@@ -258,6 +263,8 @@ upgrade to the upcoming stable release.
 [#465]: https://github.com/uber-go/zap/pull/465
 [#460]: https://github.com/uber-go/zap/pull/460
 [#470]: https://github.com/uber-go/zap/pull/470
+[#487]: https://github.com/uber-go/zap/pull/487
 [#490]: https://github.com/uber-go/zap/pull/490
 [#491]: https://github.com/uber-go/zap/pull/491
 [#491]: https://github.com/uber-go/zap/pull/439
+[#504]: https://github.com/uber-go/zap/pull/504
diff --git a/zapcore/field_test.go b/zapcore/field_test.go
index 2d8a45f9e..fb722b4b7 100644
--- a/zapcore/field_test.go
+++ b/zapcore/field_test.go
@@ -95,7 +95,7 @@ func TestFields(t *testing.T) {
 		{t: ObjectMarshalerType, iface: users(2), want: map[string]interface{}{"users": 2}},
 		{t: BinaryType, iface: []byte("foo"), want: []byte("foo")},
 		{t: BoolType, i: 0, want: false},
-		{t: ByteStringType, iface: []byte("foo"), want: []byte("foo")},
+		{t: ByteStringType, iface: []byte("foo"), want: "foo"},
 		{t: Complex128Type, iface: 1 + 2i, want: 1 + 2i},
 		{t: Complex64Type, iface: complex64(1 + 2i), want: complex64(1 + 2i)},
 		{t: DurationType, i: 1000, want: time.Microsecond},
diff --git a/zapcore/memory_encoder.go b/zapcore/memory_encoder.go
index 4805c8a94..5c46bc13d 100644
--- a/zapcore/memory_encoder.go
+++ b/zapcore/memory_encoder.go
@@ -60,7 +60,7 @@ func (m *MapObjectEncoder) AddObject(k string, v ObjectMarshaler) error {
 func (m *MapObjectEncoder) AddBinary(k string, v []byte) { m.cur[k] = v }
 
 // AddByteString implements ObjectEncoder.
-func (m *MapObjectEncoder) AddByteString(k string, v []byte) { m.cur[k] = v }
+func (m *MapObjectEncoder) AddByteString(k string, v []byte) { m.cur[k] = string(v) }
 
 // AddBool implements ObjectEncoder.
 func (m *MapObjectEncoder) AddBool(k string, v bool) { m.cur[k] = v }