diff --git a/go.mod b/go.mod
index 9160474e3..b270bda8a 100644
--- a/go.mod
+++ b/go.mod
@@ -22,7 +22,7 @@ require (
 	github.com/uber-go/tally v3.3.15+incompatible
 	github.com/uber/jaeger-client-go v2.22.1+incompatible
 	github.com/uber/jaeger-lib v2.2.0+incompatible // indirect
-	go.temporal.io/temporal-proto v0.20.27
+	go.temporal.io/temporal-proto v0.20.28
 	go.uber.org/atomic v1.6.0
 	go.uber.org/goleak v1.0.0
 	go.uber.org/zap v1.14.1
diff --git a/go.sum b/go.sum
index 6b1fced06..647633ce8 100644
--- a/go.sum
+++ b/go.sum
@@ -93,8 +93,8 @@ github.com/uber/jaeger-client-go v2.22.1+incompatible/go.mod h1:WVhlPFC8FDjOFMMW
 github.com/uber/jaeger-lib v2.2.0+incompatible h1:MxZXOiR2JuoANZ3J6DE/U0kSFv/eJ/GfSYVCjK7dyaw=
 github.com/uber/jaeger-lib v2.2.0+incompatible/go.mod h1:ComeNDZlWwrWnDv8aPp0Ba6+uUTzImX/AauajbLI56U=
 github.com/yuin/goldmark v1.1.25/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
-go.temporal.io/temporal-proto v0.20.27 h1:g/UMo4TZyUGCGCAsvz81IIlkN6YQW7S5Ua4bwpjECvQ=
-go.temporal.io/temporal-proto v0.20.27/go.mod h1:Lv8L8YBpbp0Z7V5nbvw5UD0j7x0isebhCOIDLkBqn6s=
+go.temporal.io/temporal-proto v0.20.28 h1:syCkMj1bBEqPCj4dKmPQksBKH3qXeZ+PayfsBMdQEOY=
+go.temporal.io/temporal-proto v0.20.28/go.mod h1:Lv8L8YBpbp0Z7V5nbvw5UD0j7x0isebhCOIDLkBqn6s=
 go.uber.org/atomic v1.6.0 h1:Ezj3JGmsOnG1MoRWQkPBsKLe9DwWD9QeXzTRzzldNVk=
 go.uber.org/atomic v1.6.0/go.mod h1:sABNBOSYdrvTF6hTgEIbc7YasKWGhgEQZyfxyTvoXHQ=
 go.uber.org/goleak v1.0.0 h1:qsup4IcBdlmsnGfqyLl4Ntn3C2XCCuKAE7DwHpScyUo=
diff --git a/internal/error_test.go b/internal/error_test.go
index b61d903e5..a00f5b13a 100644
--- a/internal/error_test.go
+++ b/internal/error_test.go
@@ -29,6 +29,7 @@ import (
 	"fmt"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	commonpb "go.temporal.io/temporal-proto/common"
@@ -437,8 +438,10 @@ func Test_ContinueAsNewError(t *testing.T) {
 		return NewContinueAsNewError(ctx, continueAsNewWfName, a1, a2)
 	}
 
+	headerValue, err := DefaultDataConverter.ToData("test-data")
+	assert.NoError(t, err)
 	header := &commonpb.Header{
-		Fields: map[string][]byte{"test": []byte("test-data")},
+		Fields: map[string]*commonpb.Payload{"test": headerValue},
 	}
 
 	s := &WorkflowTestSuite{
@@ -450,7 +453,7 @@ func Test_ContinueAsNewError(t *testing.T) {
 		Name: continueAsNewWfName,
 	})
 	wfEnv.ExecuteWorkflow(continueAsNewWorkflowFn, 101, "another random string")
-	err := wfEnv.GetWorkflowError()
+	err = wfEnv.GetWorkflowError()
 
 	require.Error(t, err)
 	continueAsNewErr, ok := err.(*ContinueAsNewError)
diff --git a/internal/headers.go b/internal/headers.go
index 929f90c1c..0bb6fb478 100644
--- a/internal/headers.go
+++ b/internal/headers.go
@@ -32,12 +32,12 @@ import (
 
 // HeaderWriter is an interface to write information to temporal headers
 type HeaderWriter interface {
-	Set(string, []byte)
+	Set(string, *commonpb.Payload)
 }
 
 // HeaderReader is an interface to read information from temporal headers
 type HeaderReader interface {
-	ForEachKey(handler func(string, []byte) error) error
+	ForEachKey(handler func(string, *commonpb.Payload) error) error
 }
 
 // ContextPropagator is an interface that determines what information from
@@ -62,7 +62,7 @@ type headerReader struct {
 	header *commonpb.Header
 }
 
-func (hr *headerReader) ForEachKey(handler func(string, []byte) error) error {
+func (hr *headerReader) ForEachKey(handler func(string, *commonpb.Payload) error) error {
 	if hr.header == nil {
 		return nil
 	}
@@ -83,7 +83,7 @@ type headerWriter struct {
 	header *commonpb.Header
 }
 
-func (hw *headerWriter) Set(key string, value []byte) {
+func (hw *headerWriter) Set(key string, value *commonpb.Payload) {
 	if hw.header == nil {
 		return
 	}
@@ -93,7 +93,7 @@ func (hw *headerWriter) Set(key string, value []byte) {
 // NewHeaderWriter returns a header writer interface
 func NewHeaderWriter(header *commonpb.Header) HeaderWriter {
 	if header != nil && header.Fields == nil {
-		header.Fields = make(map[string][]byte)
+		header.Fields = make(map[string]*commonpb.Payload)
 	}
 	return &headerWriter{header}
 }
diff --git a/internal/headers_test.go b/internal/headers_test.go
index e158f0868..b371fedcd 100644
--- a/internal/headers_test.go
+++ b/internal/headers_test.go
@@ -37,50 +37,50 @@ func TestHeaderWriter(t *testing.T) {
 		name     string
 		initial  *commonpb.Header
 		expected *commonpb.Header
-		vals     map[string][]byte
+		vals     map[string]*commonpb.Payload
 	}{
 		{
 			"no values",
 			&commonpb.Header{
-				Fields: map[string][]byte{},
+				Fields: map[string]*commonpb.Payload{},
 			},
 			&commonpb.Header{
-				Fields: map[string][]byte{},
+				Fields: map[string]*commonpb.Payload{},
 			},
-			map[string][]byte{},
+			map[string]*commonpb.Payload{},
 		},
 		{
 			"add values",
 			&commonpb.Header{
-				Fields: map[string][]byte{},
+				Fields: map[string]*commonpb.Payload{},
 			},
 			&commonpb.Header{
-				Fields: map[string][]byte{
-					"key1": []byte("val1"),
-					"key2": []byte("val2"),
+				Fields: map[string]*commonpb.Payload{
+					"key1": encodeString(t, "val1"),
+					"key2": encodeString(t, "val2"),
 				},
 			},
-			map[string][]byte{
-				"key1": []byte("val1"),
-				"key2": []byte("val2"),
+			map[string]*commonpb.Payload{
+				"key1": encodeString(t, "val1"),
+				"key2": encodeString(t, "val2"),
 			},
 		},
 		{
 			"overwrite values",
 			&commonpb.Header{
-				Fields: map[string][]byte{
-					"key1": []byte("unexpected"),
+				Fields: map[string]*commonpb.Payload{
+					"key1": encodeString(t, "unexpected"),
 				},
 			},
 			&commonpb.Header{
-				Fields: map[string][]byte{
-					"key1": []byte("val1"),
-					"key2": []byte("val2"),
+				Fields: map[string]*commonpb.Payload{
+					"key1": encodeString(t, "val1"),
+					"key2": encodeString(t, "val2"),
 				},
 			},
-			map[string][]byte{
-				"key1": []byte("val1"),
-				"key2": []byte("val2"),
+			map[string]*commonpb.Payload{
+				"key1": encodeString(t, "val1"),
+				"key2": encodeString(t, "val2"),
 			},
 		},
 	}
@@ -98,6 +98,12 @@ func TestHeaderWriter(t *testing.T) {
 	}
 }
 
+func encodeString(t *testing.T, s string) *commonpb.Payload {
+	p, err := DefaultDataConverter.ToData(s)
+	assert.NoError(t, err)
+	return p
+}
+
 func TestHeaderReader(t *testing.T) {
 	t.Parallel()
 	tests := []struct {
@@ -109,9 +115,9 @@ func TestHeaderReader(t *testing.T) {
 		{
 			"valid values",
 			&commonpb.Header{
-				Fields: map[string][]byte{
-					"key1": []byte("val1"),
-					"key2": []byte("val2"),
+				Fields: map[string]*commonpb.Payload{
+					"key1": encodeString(t, "val1"),
+					"key2": encodeString(t, "val2"),
 				},
 			},
 			map[string]struct{}{"key1": {}, "key2": {}},
@@ -120,9 +126,9 @@ func TestHeaderReader(t *testing.T) {
 		{
 			"invalid values",
 			&commonpb.Header{
-				Fields: map[string][]byte{
-					"key1": []byte("val1"),
-					"key2": []byte("val2"),
+				Fields: map[string]*commonpb.Payload{
+					"key1": encodeString(t, "val1"),
+					"key2": encodeString(t, "val2"),
 				},
 			},
 			map[string]struct{}{"key2": {}},
@@ -135,7 +141,7 @@ func TestHeaderReader(t *testing.T) {
 		t.Run(test.name, func(t *testing.T) {
 			t.Parallel()
 			reader := NewHeaderReader(test.header)
-			err := reader.ForEachKey(func(key string, val []byte) error {
+			err := reader.ForEachKey(func(key string, _ *commonpb.Payload) error {
 				if _, ok := test.keys[key]; !ok {
 					return assert.AnError
 				}
diff --git a/internal/internal_workflow.go b/internal/internal_workflow.go
index 46283597a..e88efe881 100644
--- a/internal/internal_workflow.go
+++ b/internal/internal_workflow.go
@@ -1194,7 +1194,7 @@ func getContextPropagatorsFromWorkflowContext(ctx Context) []ContextPropagator {
 
 func getHeadersFromContext(ctx Context) *commonpb.Header {
 	header := &commonpb.Header{
-		Fields: make(map[string][]byte),
+		Fields: make(map[string]*commonpb.Payload),
 	}
 	contextPropagators := getContextPropagatorsFromWorkflowContext(ctx)
 	for _, ctxProp := range contextPropagators {
diff --git a/internal/internal_workflow_client.go b/internal/internal_workflow_client.go
index e148a3ab7..b02acec5f 100644
--- a/internal/internal_workflow_client.go
+++ b/internal/internal_workflow_client.go
@@ -948,7 +948,7 @@ func (wc *WorkflowClient) CloseConnection() error {
 
 func (wc *WorkflowClient) getWorkflowHeader(ctx context.Context) *commonpb.Header {
 	header := &commonpb.Header{
-		Fields: make(map[string][]byte),
+		Fields: make(map[string]*commonpb.Payload),
 	}
 	writer := NewHeaderWriter(header)
 	for _, ctxProp := range wc.contextPropagators {
diff --git a/internal/internal_workflow_client_test.go b/internal/internal_workflow_client_test.go
index f30f0df59..b4886a0d6 100644
--- a/internal/internal_workflow_client_test.go
+++ b/internal/internal_workflow_client_test.go
@@ -92,7 +92,11 @@ func (s *stringMapPropagator) Inject(ctx context.Context, writer HeaderWriter) e
 		if !ok {
 			return fmt.Errorf("unable to extract key from context %v", key)
 		}
-		writer.Set(key, []byte(value))
+		encodedValue, err := DefaultDataConverter.ToData(value)
+		if err != nil {
+			return err
+		}
+		writer.Set(key, encodedValue)
 	}
 	return nil
 }
@@ -104,16 +108,25 @@ func (s *stringMapPropagator) InjectFromWorkflow(ctx Context, writer HeaderWrite
 		if !ok {
 			return fmt.Errorf("unable to extract key from context %v", key)
 		}
-		writer.Set(key, []byte(value))
+		encodedValue, err := DefaultDataConverter.ToData(value)
+		if err != nil {
+			return err
+		}
+		writer.Set(key, encodedValue)
 	}
 	return nil
 }
 
 // Extract extracts values from headers and puts them into context
 func (s *stringMapPropagator) Extract(ctx context.Context, reader HeaderReader) (context.Context, error) {
-	if err := reader.ForEachKey(func(key string, value []byte) error {
+	if err := reader.ForEachKey(func(key string, value *commonpb.Payload) error {
 		if _, ok := s.keys[key]; ok {
-			ctx = context.WithValue(ctx, contextKey(key), string(value))
+			var decodedValue string
+			err := DefaultDataConverter.FromData(value, &decodedValue)
+			if err != nil {
+				return err
+			}
+			ctx = context.WithValue(ctx, contextKey(key), decodedValue)
 		}
 		return nil
 	}); err != nil {
@@ -124,9 +137,14 @@ func (s *stringMapPropagator) Extract(ctx context.Context, reader HeaderReader)
 
 // ExtractToWorkflow extracts values from headers and puts them into context
 func (s *stringMapPropagator) ExtractToWorkflow(ctx Context, reader HeaderReader) (Context, error) {
-	if err := reader.ForEachKey(func(key string, value []byte) error {
+	if err := reader.ForEachKey(func(key string, value *commonpb.Payload) error {
 		if _, ok := s.keys[key]; ok {
-			ctx = WithValue(ctx, contextKey(key), string(value))
+			var decodedValue string
+			err := DefaultDataConverter.FromData(value, &decodedValue)
+			if err != nil {
+				return err
+			}
+			ctx = WithValue(ctx, contextKey(key), decodedValue)
 		}
 		return nil
 	}); err != nil {
diff --git a/internal/internal_workflow_testsuite_test.go b/internal/internal_workflow_testsuite_test.go
index cf40aa878..59cd539f6 100644
--- a/internal/internal_workflow_testsuite_test.go
+++ b/internal/internal_workflow_testsuite_test.go
@@ -61,7 +61,7 @@ func (s *WorkflowTestSuiteUnitTest) SetupSuite() {
 		ScheduleToCloseTimeout: 3 * time.Second,
 	}
 	s.header = &commonpb.Header{
-		Fields: map[string][]byte{"test": []byte("test-data")},
+		Fields: map[string]*commonpb.Payload{"test": encodeString(s.T(), "test-data")},
 	}
 	s.contextPropagators = []ContextPropagator{NewStringMapPropagator([]string{"test"})}
 }
@@ -387,8 +387,8 @@ func (s *WorkflowTestSuiteUnitTest) Test_ActivityWithHeaderContext() {
 	}
 
 	s.SetHeader(&commonpb.Header{
-		Fields: map[string][]byte{
-			testHeader: []byte("test-data"),
+		Fields: map[string]*commonpb.Payload{
+			testHeader: encodeString(s.T(), "test-data"),
 		},
 	})
 
@@ -1609,8 +1609,8 @@ func (s *WorkflowTestSuiteUnitTest) Test_WorkflowHeaderContext() {
 
 	s.SetContextPropagators([]ContextPropagator{NewStringMapPropagator([]string{testHeader})})
 	s.SetHeader(&commonpb.Header{
-		Fields: map[string][]byte{
-			testHeader: []byte("test-data"),
+		Fields: map[string]*commonpb.Payload{
+			testHeader: encodeString(s.T(), "test-data"),
 		},
 	})
 
diff --git a/internal/tracer.go b/internal/tracer.go
index 297191af1..83c713be5 100644
--- a/internal/tracer.go
+++ b/internal/tracer.go
@@ -28,6 +28,7 @@ import (
 	"context"
 
 	"github.com/opentracing/opentracing-go"
+	commonpb "go.temporal.io/temporal-proto/common"
 	"go.uber.org/zap"
 )
 
@@ -35,9 +36,17 @@ type tracingReader struct {
 	reader HeaderReader
 }
 
+// This is important requirement for t.tracer.Extract to work.
+var _ opentracing.TextMapReader = (*tracingReader)(nil)
+
 func (t tracingReader) ForeachKey(handler func(key, val string) error) error {
-	return t.reader.ForEachKey(func(k string, v []byte) error {
-		return handler(k, string(v))
+	return t.reader.ForEachKey(func(k string, v *commonpb.Payload) error {
+		var decodedValue string
+		err := DefaultDataConverter.FromData(v, &decodedValue)
+		if err != nil {
+			return err
+		}
+		return handler(k, decodedValue)
 	})
 }
 
@@ -45,8 +54,12 @@ type tracingWriter struct {
 	writer HeaderWriter
 }
 
+// This is important requirement for t.tracer.Inject to work.
+var _ opentracing.TextMapWriter = (*tracingWriter)(nil)
+
 func (t tracingWriter) Set(key, val string) {
-	t.writer.Set(key, []byte(val))
+	encodedValue, _ := DefaultDataConverter.ToData(val)
+	t.writer.Set(key, encodedValue)
 }
 
 // tracingContextPropagator implements the ContextPropagator interface for
diff --git a/internal/tracer_test.go b/internal/tracer_test.go
index 003a73cb6..ef79dbbbe 100644
--- a/internal/tracer_test.go
+++ b/internal/tracer_test.go
@@ -47,7 +47,7 @@ func TestTracingContextPropagator(t *testing.T) {
 	ctx := context.Background()
 	ctx = opentracing.ContextWithSpan(ctx, span)
 	header := &commonpb.Header{
-		Fields: map[string][]byte{},
+		Fields: map[string]*commonpb.Payload{},
 	}
 
 	err = ctxProp.Inject(ctx, NewHeaderWriter(header))
@@ -66,7 +66,7 @@ func TestTracingContextPropagatorNoSpan(t *testing.T) {
 	ctxProp := NewTracingContextPropagator(zap.NewNop(), opentracing.NoopTracer{})
 
 	header := &commonpb.Header{
-		Fields: map[string][]byte{},
+		Fields: map[string]*commonpb.Payload{},
 	}
 	err := ctxProp.Inject(context.Background(), NewHeaderWriter(header))
 	require.NoError(t, err)
@@ -87,7 +87,7 @@ func TestTracingContextPropagatorWorkflowContext(t *testing.T) {
 	assert.NotNil(t, span.Context())
 	ctx := contextWithSpan(Background(), span.Context())
 	header := &commonpb.Header{
-		Fields: map[string][]byte{},
+		Fields: map[string]*commonpb.Payload{},
 	}
 
 	err = ctxProp.InjectFromWorkflow(ctx, NewHeaderWriter(header))
@@ -111,7 +111,7 @@ func TestTracingContextPropagatorWorkflowContextNoSpan(t *testing.T) {
 	ctxProp := NewTracingContextPropagator(zap.NewNop(), opentracing.NoopTracer{})
 
 	header := &commonpb.Header{
-		Fields: map[string][]byte{},
+		Fields: map[string]*commonpb.Payload{},
 	}
 	err := ctxProp.InjectFromWorkflow(Background(), NewHeaderWriter(header))
 	require.NoError(t, err)
diff --git a/internal/workflow.go b/internal/workflow.go
index 78a0d4370..623446ec5 100644
--- a/internal/workflow.go
+++ b/internal/workflow.go
@@ -695,7 +695,7 @@ func (wc *workflowEnvironmentInterceptor) ExecuteChildWorkflow(ctx Context, chil
 
 func getWorkflowHeader(ctx Context, ctxProps []ContextPropagator) *commonpb.Header {
 	header := &commonpb.Header{
-		Fields: make(map[string][]byte),
+		Fields: make(map[string]*commonpb.Payload),
 	}
 	writer := NewHeaderWriter(header)
 	for _, ctxProp := range ctxProps {