diff --git a/client_test.go b/client_test.go
index 152f40ca1..d164dd6f7 100644
--- a/client_test.go
+++ b/client_test.go
@@ -13,6 +13,7 @@ import (
 	"github.com/google/go-cmp/cmp"
 	"github.com/google/go-cmp/cmp/cmpopts"
 	pkgErrors "github.com/pkg/errors"
+	"github.com/stretchr/testify/require"
 )
 
 func TestNewClientAllowsEmptyDSN(t *testing.T) {
@@ -609,6 +610,7 @@ func TestSampleRate(t *testing.T) {
 func BenchmarkProcessEvent(b *testing.B) {
 	c, err := NewClient(ClientOptions{
 		SampleRate: 0.25,
+		Transport:  &TransportMock{},
 	})
 	if err != nil {
 		b.Fatal(err)
@@ -708,8 +710,17 @@ func TestCustomMaxSpansProperty(t *testing.T) {
 	assertEqual(t, client.Options().MaxSpans, 2000)
 
 	properClient, _ := NewClient(ClientOptions{
-		MaxSpans: 3000,
+		MaxSpans:  3000,
+		Transport: &TransportMock{},
 	})
 
 	assertEqual(t, properClient.Options().MaxSpans, 3000)
 }
+
+func TestClientSetsUpTransport(t *testing.T) {
+	client, _ := NewClient(ClientOptions{Dsn: testDsn})
+	require.IsType(t, &HTTPTransport{}, client.Transport)
+
+	client, _ = NewClient(ClientOptions{})
+	require.IsType(t, &noopTransport{}, client.Transport)
+}
diff --git a/hub_test.go b/hub_test.go
index 23ae3746f..46b889774 100644
--- a/hub_test.go
+++ b/hub_test.go
@@ -13,7 +13,7 @@ import (
 const testDsn = "http://whatever@example.com/1337"
 
 func setupHubTest() (*Hub, *Client, *Scope) {
-	client, _ := NewClient(ClientOptions{Dsn: testDsn})
+	client, _ := NewClient(ClientOptions{Dsn: testDsn, Transport: &TransportMock{}})
 	scope := NewScope()
 	hub := NewHub(client, scope)
 	return hub, client, scope
@@ -95,7 +95,7 @@ func TestPopScopeCannotLeaveStackEmpty(t *testing.T) {
 func TestBindClient(t *testing.T) {
 	hub, client, _ := setupHubTest()
 	hub.PushScope()
-	newClient, _ := NewClient(ClientOptions{Dsn: testDsn})
+	newClient, _ := NewClient(ClientOptions{Dsn: testDsn, Transport: &TransportMock{}})
 	hub.BindClient(newClient)
 
 	if (*hub.stack)[0].client == (*hub.stack)[1].client {
@@ -123,7 +123,7 @@ func TestWithScopeBindClient(t *testing.T) {
 	hub, client, _ := setupHubTest()
 
 	hub.WithScope(func(scope *Scope) {
-		newClient, _ := NewClient(ClientOptions{Dsn: testDsn})
+		newClient, _ := NewClient(ClientOptions{Dsn: testDsn, Transport: &TransportMock{}})
 		hub.BindClient(newClient)
 		if hub.stackTop().client != newClient {
 			t.Error("should use newly bound client")
diff --git a/tracing_test.go b/tracing_test.go
index 5bb0e364b..61848cb0a 100644
--- a/tracing_test.go
+++ b/tracing_test.go
@@ -362,6 +362,9 @@ type testContextKey struct{}
 type testContextValue struct{}
 
 func NewTestContext(options ClientOptions) context.Context {
+	if options.Transport == nil {
+		options.Transport = &TransportMock{}
+	}
 	client, err := NewClient(options)
 	if err != nil {
 		panic(err)