diff --git a/.github/variables/go-versions.env b/.github/variables/go-versions.env
index 3c277c3..cb4024a 100644
--- a/.github/variables/go-versions.env
+++ b/.github/variables/go-versions.env
@@ -1,3 +1,3 @@
-latest=1.22
-penultimate=1.21
-min=1.17
+latest=1.24
+penultimate=1.23
+min=1.23
diff --git a/.github/workflows/go-versions.yml b/.github/workflows/go-versions.yml
index 86090db..5de11c7 100644
--- a/.github/workflows/go-versions.yml
+++ b/.github/workflows/go-versions.yml
@@ -49,4 +49,8 @@ jobs:
       - name: Set Go Version Matrices
         id: set-matrix
         run: |
-          echo "all=[\"${{ steps.set-env.outputs.latest }}\",\"${{ steps.set-env.outputs.penultimate }}\",\"${{ steps.set-env.outputs.min }}\"]" >> $GITHUB_OUTPUT
+          if [ "${{ steps.set-env.outputs.penultimate }}" == "${{ steps.set-env.outputs.min }}" ]; then
+            echo "all=[\"${{ steps.set-env.outputs.latest }}\",\"${{ steps.set-env.outputs.penultimate }}\"]" >> $GITHUB_OUTPUT
+          else
+            echo "all=[\"${{ steps.set-env.outputs.latest }}\",\"${{ steps.set-env.outputs.penultimate }}\",\"${{ steps.set-env.outputs.min }}\"]" >> $GITHUB_OUTPUT
+          fi
diff --git a/.golangci.yml b/.golangci.yml
index a592413..1caf2a0 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -1,26 +1,17 @@
+version: "2"
 run:
-  deadline: 120s
   tests: false
-
 linters:
   enable:
     - bodyclose
     - dupl
-    - errcheck
-    - exportloopref
-    - goconst
     - gochecknoglobals
     - gochecknoinits
     - goconst
     - gocritic
     - gocyclo
     - godox
-    - gofmt
-    - goimports
     - gosec
-    - gosimple
-    - govet
-    - ineffassign
     - lll
     - misspell
     - nakedret
@@ -28,20 +19,31 @@ linters:
     - prealloc
     - revive
     - staticcheck
-    - stylecheck
-    - typecheck
     - unconvert
     - unparam
-    - unused
     - whitespace
-  fast: false
-
-linters-settings:
-  gofmt:
-    simplify: false
-  goimports:
-    local-prefixes: github.com/launchdarkly
-
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
 issues:
-  exclude-use-default: false
   max-same-issues: 1000
+formatters:
+  enable:
+    - gofmt
+    - goimports
+  settings:
+    gofmt:
+      simplify: false
+    goimports:
+      local-prefixes:
+        - gopkg.in/launchdarkly
+        - github.com/launchdarkly
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
diff --git a/Makefile b/Makefile
index c52ae2b..9c7b988 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-GOLANGCI_LINT_VERSION=v1.60.1
+GOLANGCI_LINT_VERSION=v1.64.5
 
 LINTER=./bin/golangci-lint
 LINTER_VERSION_FILE=./bin/.golangci-lint-version-$(GOLANGCI_LINT_VERSION)
diff --git a/contract-tests/go.mod b/contract-tests/go.mod
index abd7a70..0900a0b 100644
--- a/contract-tests/go.mod
+++ b/contract-tests/go.mod
@@ -1,6 +1,6 @@
 module github.com/launchdarkly/eventsource/contract-tests
 
-go 1.17
+go 1.23
 
 replace github.com/launchdarkly/eventsource => ../
 
diff --git a/contract-tests/go.sum b/contract-tests/go.sum
index d26315c..acf1872 100644
--- a/contract-tests/go.sum
+++ b/contract-tests/go.sum
@@ -1,17 +1,10 @@
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/launchdarkly/go-test-helpers/v2 v2.2.0 h1:L3kGILP/6ewikhzhdNkHy1b5y4zs50LueWenVF0sBbs=
-github.com/launchdarkly/go-test-helpers/v2 v2.2.0/go.mod h1:L7+th5govYp5oKU9iN7To5PgznBuIjBPn+ejqKR0avw=
+github.com/launchdarkly/go-test-helpers/v3 v3.1.0 h1:E3bxJMzMoA+cJSF3xxtk2/chr1zshl1ZWa0/oR+8bvg=
+github.com/launchdarkly/go-test-helpers/v3 v3.1.0/go.mod h1:Ake5+hZFS/DmIGKx/cizhn5W9pGA7pplcR7xCxWiLIo=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.6.0 h1:jlIyCplCJFULU/01vCkhKuTyc3OorI3bJFuw6obfgho=
 github.com/stretchr/testify v1.6.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0 h1:hjy8E9ON/egN1tAYqKb61G10WtihqetD4sz2H+8nIeA=
 gopkg.in/yaml.v3 v3.0.0/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/decoder.go b/decoder.go
index 4e5ec4a..2e84e0a 100644
--- a/decoder.go
+++ b/decoder.go
@@ -3,6 +3,7 @@ package eventsource
 import (
 	"bufio"
 	"io"
+	"net/http"
 	"strconv"
 	"strings"
 	"time"
@@ -10,6 +11,7 @@ import (
 
 type publication struct {
 	id, event, data, lastEventID string
+	headers                      http.Header
 	retry                        int64
 }
 
@@ -22,12 +24,21 @@ func (s *publication) Retry() int64  { return s.retry }
 // LastEventID is from a separate interface, EventWithLastID
 func (s *publication) LastEventID() string { return s.lastEventID }
 
+// Headers is from a separate interface, EventWithHeaders
+func (s *publication) Headers() http.Header {
+	if s.headers == nil {
+		return nil
+	}
+	return s.headers.Clone()
+}
+
 // A Decoder is capable of reading Events from a stream.
 type Decoder struct {
 	linesCh     <-chan string
 	errorCh     <-chan error
 	readTimeout time.Duration
 	lastEventID string
+	headers     http.Header
 }
 
 // DecoderOption is a common interface for optional configuration parameters that can be
@@ -48,6 +59,12 @@ func (o lastEventIDDecoderOption) apply(d *Decoder) {
 	d.lastEventID = string(o)
 }
 
+type headersDecoderOption http.Header
+
+func (o headersDecoderOption) apply(d *Decoder) {
+	d.headers = http.Header(o)
+}
+
 // DecoderOptionReadTimeout returns an option that sets the read timeout interval for a
 // Decoder when the Decoder is created. If the Decoder does not receive new data within this
 // length of time, it will return an error. By default, there is no read timeout.
@@ -62,6 +79,13 @@ func DecoderOptionLastEventID(lastEventID string) DecoderOption {
 	return lastEventIDDecoderOption(lastEventID)
 }
 
+// DecoderOptionHeaders returns an option that sets the Headers property for a
+// Decoder when the Decoder is created. This allows access to the HTTP response
+// headers for the event.
+func DecoderOptionHeaders(headers http.Header) DecoderOption {
+	return headersDecoderOption(headers)
+}
+
 // NewDecoder returns a new Decoder instance that reads events with the given io.Reader.
 func NewDecoder(r io.Reader) *Decoder {
 	bufReader := bufio.NewReader(newNormaliser(r))
@@ -152,6 +176,7 @@ ReadLoop:
 	}
 	pub.data = strings.TrimSuffix(pub.data, "\n")
 	pub.lastEventID = dec.lastEventID
+	pub.headers = dec.headers
 	return pub, nil
 }
 
diff --git a/decoder_test.go b/decoder_test.go
index f306e13..a56ac3a 100644
--- a/decoder_test.go
+++ b/decoder_test.go
@@ -2,6 +2,7 @@ package eventsource
 
 import (
 	"io"
+	"net/http"
 	"strings"
 	"testing"
 
@@ -57,6 +58,13 @@ func requireLastEventID(t *testing.T, event Event) string {
 	return eventWithID.LastEventID()
 }
 
+func requireHeaders(t *testing.T, event Event) http.Header {
+	// necessary because we can't yet add Headers to the basic Event interface; see EventWithHeaders
+	eventWithHeaders, ok := event.(EventWithHeaders)
+	require.True(t, ok, "event should have implemented EventWithHeaders")
+	return eventWithHeaders.Headers()
+}
+
 func TestDecoderTracksLastEventID(t *testing.T) {
 	t.Run("uses last ID that is passed in options", func(t *testing.T) {
 		inputData := "data: abc\n\n"
@@ -96,8 +104,8 @@ func TestDecoderTracksLastEventID(t *testing.T) {
 		assert.Equal(t, "def", requireLastEventID(t, event3))
 	})
 
-	t.Run("last ID persists if not overridden", func(t *testing.T) {
-		inputData := "id: abc\ndata: first\n\ndata: second\n\nid: def\ndata:third\n\n"
+	t.Run("last ID can be overridden with empty string", func(t *testing.T) {
+		inputData := "id: abc\ndata: first\n\nid: \ndata: second\n\n"
 		decoder := NewDecoderWithOptions(strings.NewReader(inputData), DecoderOptionLastEventID("my-id"))
 
 		event1, err := decoder.Decode()
@@ -112,32 +120,57 @@ func TestDecoderTracksLastEventID(t *testing.T) {
 
 		assert.Equal(t, "second", event2.Data())
 		assert.Equal(t, "", event2.Id())
-		assert.Equal(t, "abc", requireLastEventID(t, event2))
+		assert.Equal(t, "", requireLastEventID(t, event2))
+	})
+}
 
-		event3, err := decoder.Decode()
+func TestDecoderTracksHeaders(t *testing.T) {
+	t.Run("event headers is nil if not provided in options", func(t *testing.T) {
+		inputData := "data: abc\n\n"
+
+		decoder := NewDecoderWithOptions(strings.NewReader(inputData))
+
+		event, err := decoder.Decode()
 		require.NoError(t, err)
 
-		assert.Equal(t, "third", event3.Data())
-		assert.Equal(t, "def", event3.Id())
-		assert.Equal(t, "def", requireLastEventID(t, event3))
+		assert.Equal(t, "abc", event.Data())
+		assert.Equal(t, "", event.Id())
+		assert.Nil(t, requireHeaders(t, event))
 	})
 
-	t.Run("last ID can be overridden with empty string", func(t *testing.T) {
-		inputData := "id: abc\ndata: first\n\nid: \ndata: second\n\n"
-		decoder := NewDecoderWithOptions(strings.NewReader(inputData), DecoderOptionLastEventID("my-id"))
+	t.Run("uses headers that are passed in options", func(t *testing.T) {
+		inputData := "data: abc\n\n"
+		headers := http.Header{
+			"X-Ld-Envid": {"env-id"},
+		}
 
-		event1, err := decoder.Decode()
+		decoder := NewDecoderWithOptions(strings.NewReader(inputData), DecoderOptionHeaders(headers))
+
+		event, err := decoder.Decode()
 		require.NoError(t, err)
 
-		assert.Equal(t, "first", event1.Data())
-		assert.Equal(t, "abc", event1.Id())
-		assert.Equal(t, "abc", requireLastEventID(t, event1))
+		assert.Equal(t, "abc", event.Data())
+		assert.Equal(t, "", event.Id())
+		assert.Equal(t, headers, requireHeaders(t, event))
+	})
 
-		event2, err := decoder.Decode()
+	t.Run("event headers are immutable", func(t *testing.T) {
+		inputData := "data: abc\n\n"
+		headers := http.Header{
+			"X-Ld-Envid": {"env-id"},
+		}
+
+		decoder := NewDecoderWithOptions(strings.NewReader(inputData), DecoderOptionHeaders(headers))
+
+		event, err := decoder.Decode()
 		require.NoError(t, err)
 
-		assert.Equal(t, "second", event2.Data())
-		assert.Equal(t, "", event2.Id())
-		assert.Equal(t, "", requireLastEventID(t, event2))
+		eventHeaders := requireHeaders(t, event)
+		assert.Equal(t, "abc", event.Data())
+		assert.Equal(t, "", event.Id())
+		assert.Equal(t, headers, eventHeaders)
+
+		eventHeaders.Add("New-Header", "new-value")
+		assert.NotContains(t, headers, "New-Header")
 	})
 }
diff --git a/go.mod b/go.mod
index 0188e78..2a71659 100644
--- a/go.mod
+++ b/go.mod
@@ -1,9 +1,9 @@
 module github.com/launchdarkly/eventsource
 
-go 1.17
+go 1.23
 
 require (
-	github.com/launchdarkly/go-test-helpers/v2 v2.2.0
+	github.com/launchdarkly/go-test-helpers/v3 v3.1.0
 	github.com/stretchr/testify v1.6.0
 )
 
diff --git a/go.sum b/go.sum
index 5c4b8ff..f6afd00 100644
--- a/go.sum
+++ b/go.sum
@@ -1,18 +1,15 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/launchdarkly/go-test-helpers/v2 v2.2.0 h1:L3kGILP/6ewikhzhdNkHy1b5y4zs50LueWenVF0sBbs=
-github.com/launchdarkly/go-test-helpers/v2 v2.2.0/go.mod h1:L7+th5govYp5oKU9iN7To5PgznBuIjBPn+ejqKR0avw=
+github.com/launchdarkly/go-test-helpers/v3 v3.1.0 h1:E3bxJMzMoA+cJSF3xxtk2/chr1zshl1ZWa0/oR+8bvg=
+github.com/launchdarkly/go-test-helpers/v3 v3.1.0/go.mod h1:Ake5+hZFS/DmIGKx/cizhn5W9pGA7pplcR7xCxWiLIo=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 github.com/stretchr/testify v1.6.0 h1:jlIyCplCJFULU/01vCkhKuTyc3OorI3bJFuw6obfgho=
 github.com/stretchr/testify v1.6.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0 h1:hjy8E9ON/egN1tAYqKb61G10WtihqetD4sz2H+8nIeA=
 gopkg.in/yaml.v3 v3.0.0/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/interface.go b/interface.go
index ba4a8a0..112dd5a 100644
--- a/interface.go
+++ b/interface.go
@@ -5,6 +5,8 @@
 // If the Repository interface is implemented on the server, events can be replayed in case of a network disconnection.
 package eventsource
 
+import "net/http"
+
 // Event is the interface for any event received by the client or sent by the server.
 type Event interface {
 	// Id is an identifier that can be used to allow a client to replay
@@ -32,6 +34,19 @@ type EventWithLastID interface {
 	LastEventID() string
 }
 
+// EventWithHeaders is an additional interface for an event received by the client,
+// allowing access to the HTTP response headers.
+//
+// This is defined as a separate interface for backward compatibility, since this
+// feature was added after the Event interface had been defined and adding a method
+// to Event would break existing implementations. All events returned by Stream do
+// implement this interface, and in a future major version the Event type will be
+// changed to always include this field.
+type EventWithHeaders interface {
+	// Headers provides access to the HTTP response headers for the event.
+	Headers() http.Header
+}
+
 // Repository is an interface to be used with Server.Register() allowing clients to replay previous events
 // through the server, if history is required.
 type Repository interface {
diff --git a/stream.go b/stream.go
index 2293960..5d886e0 100644
--- a/stream.go
+++ b/stream.go
@@ -4,7 +4,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"net/http"
 	"net/url"
 	"sync"
@@ -127,9 +126,9 @@ func SubscribeWithRequestAndOptions(request *http.Request, options ...StreamOpti
 		initialRetryTimeoutCh = time.After(configuredOptions.initialRetryTimeout)
 	}
 	for {
-		r, err := stream.connect()
+		r, h, err := stream.connect()
 		if err == nil {
-			go stream.stream(r)
+			go stream.stream(r, h)
 			return stream, nil
 		}
 		lastError = err
@@ -229,7 +228,7 @@ func (stream *Stream) Close() {
 	})
 }
 
-func (stream *Stream) connect() (io.ReadCloser, error) {
+func (stream *Stream) connect() (io.ReadCloser, http.Header, error) {
 	var err error
 	var resp *http.Response
 	stream.req.Header.Set("Cache-Control", "no-cache")
@@ -245,28 +244,28 @@ func (stream *Stream) connect() (io.ReadCloser, error) {
 	// All but the initial connection will need to regenerate the body
 	if stream.connections > 0 && req.GetBody != nil {
 		if req.Body, err = req.GetBody(); err != nil {
-			return nil, err
+			return nil, nil, err
 		}
 	}
 
 	if resp, err = stream.c.Do(&req); err != nil {
-		return nil, err
+		return nil, nil, err
 	}
 	stream.connections++
 	if resp.StatusCode != 200 {
-		message, _ := ioutil.ReadAll(resp.Body)
+		message, _ := io.ReadAll(resp.Body)
 		_ = resp.Body.Close()
 		err = SubscriptionError{
 			Code:    resp.StatusCode,
 			Message: string(message),
 			Header:  resp.Header,
 		}
-		return nil, err
+		return nil, nil, err
 	}
-	return resp.Body, nil
+	return resp.Body, resp.Header, nil
 }
 
-func (stream *Stream) stream(r io.ReadCloser) {
+func (stream *Stream) stream(r io.ReadCloser, h http.Header) {
 	retryChan := make(chan struct{}, 1)
 
 	scheduleRetry := func() {
@@ -302,6 +301,7 @@ NewStream:
 			dec := NewDecoderWithOptions(r,
 				DecoderOptionReadTimeout(stream.readTimeout),
 				DecoderOptionLastEventID(stream.lastEventID),
+				DecoderOptionHeaders(h),
 			)
 			go func() {
 				for {
@@ -358,9 +358,10 @@ NewStream:
 				break NewStream
 			case <-retryChan:
 				var err error
-				r, err = stream.connect()
+				r, h, err = stream.connect()
 				if err != nil {
 					r = nil
+					h = nil
 					if !reportErrorAndMaybeContinue(err) {
 						break NewStream
 					}
diff --git a/stream_error_after_subscribe_test.go b/stream_error_after_subscribe_test.go
index 33767aa..5e3774b 100644
--- a/stream_error_after_subscribe_test.go
+++ b/stream_error_after_subscribe_test.go
@@ -8,7 +8,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/launchdarkly/go-test-helpers/v2/httphelpers"
+	"github.com/launchdarkly/go-test-helpers/v3/httphelpers"
 )
 
 func TestStreamErrorsAreSentToErrorsChannel(t *testing.T) {
diff --git a/stream_error_during_subscribe_test.go b/stream_error_during_subscribe_test.go
index 1c7cc8b..5ce3f1a 100644
--- a/stream_error_during_subscribe_test.go
+++ b/stream_error_during_subscribe_test.go
@@ -9,7 +9,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/launchdarkly/go-test-helpers/v2/httphelpers"
+	"github.com/launchdarkly/go-test-helpers/v3/httphelpers"
 )
 
 func handlerCausingNetworkError() http.Handler {
diff --git a/stream_reading_test.go b/stream_reading_test.go
index cbe37db..b438853 100644
--- a/stream_reading_test.go
+++ b/stream_reading_test.go
@@ -7,7 +7,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/launchdarkly/go-test-helpers/v2/httphelpers"
+	"github.com/launchdarkly/go-test-helpers/v3/httphelpers"
 )
 
 func TestStreamSubscribeEventsChan(t *testing.T) {
@@ -23,7 +23,31 @@ func TestStreamSubscribeEventsChan(t *testing.T) {
 
 	select {
 	case receivedEvent := <-stream.Events:
-		assert.Equal(t, &publication{id: "123", lastEventID: "123"}, receivedEvent)
+		receivedWithLastId := receivedEvent.(EventWithLastID)
+		receivedWithHeaders := receivedEvent.(EventWithHeaders)
+		assert.Equal(t, "123", receivedEvent.Id())
+		assert.Equal(t, "123", receivedWithLastId.LastEventID())
+		assert.NotEmpty(t, receivedWithHeaders.Headers())
+	case <-time.After(timeToWaitForEvent):
+		t.Error("Timed out waiting for event")
+	}
+}
+
+func TestStreamCanReadSpecificHeader(t *testing.T) {
+	streamHandler, streamControl := httphelpers.SSEHandlerWithEnvironmentID(nil, "env-id")
+	defer streamControl.Close()
+	httpServer := httptest.NewServer(streamHandler)
+	defer httpServer.Close()
+
+	stream := mustSubscribe(t, httpServer.URL)
+	defer stream.Close()
+
+	streamControl.Send(httphelpers.SSEEvent{ID: "123"})
+
+	select {
+	case receivedEvent := <-stream.Events:
+		receivedWithHeaders := receivedEvent.(EventWithHeaders)
+		assert.Equal(t, "env-id", receivedWithHeaders.Headers().Get("X-Ld-Envid"))
 	case <-time.After(timeToWaitForEvent):
 		t.Error("Timed out waiting for event")
 	}
diff --git a/stream_reconnect_test.go b/stream_reconnect_test.go
index db51e4c..a284d93 100644
--- a/stream_reconnect_test.go
+++ b/stream_reconnect_test.go
@@ -7,7 +7,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/launchdarkly/go-test-helpers/v2/httphelpers"
+	"github.com/launchdarkly/go-test-helpers/v3/httphelpers"
 )
 
 func TestStreamReconnectsIfConnectionIsBroken(t *testing.T) {
@@ -49,7 +49,11 @@ func TestStreamReconnectsIfConnectionIsBroken(t *testing.T) {
 			t.Error("Timed out waiting for event")
 			return
 		case receivedEvent := <-stream.Events:
-			assert.Equal(t, &publication{id: "123", lastEventID: "123"}, receivedEvent)
+			receivedWithLastId := receivedEvent.(EventWithLastID)
+			receivedWithHeaders := receivedEvent.(EventWithHeaders)
+			assert.Equal(t, "123", receivedEvent.Id())
+			assert.Equal(t, "123", receivedWithLastId.LastEventID())
+			assert.NotEmpty(t, receivedWithHeaders.Headers())
 			return
 		}
 	}
diff --git a/stream_requests_test.go b/stream_requests_test.go
index d98fb52..ea800ce 100644
--- a/stream_requests_test.go
+++ b/stream_requests_test.go
@@ -11,7 +11,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/launchdarkly/go-test-helpers/v2/httphelpers"
+	"github.com/launchdarkly/go-test-helpers/v3/httphelpers"
 )
 
 func TestStreamCanUseCustomClient(t *testing.T) {
diff --git a/stream_restart_close_test.go b/stream_restart_close_test.go
index 7fab2d7..18135b0 100644
--- a/stream_restart_close_test.go
+++ b/stream_restart_close_test.go
@@ -7,7 +7,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/launchdarkly/go-test-helpers/v2/httphelpers"
+	"github.com/launchdarkly/go-test-helpers/v3/httphelpers"
 )
 
 func toPublication(e httphelpers.SSEEvent) *publication {