diff --git a/client_test.go b/client_test.go
index eb64d3db..d7d54d3a 100644
--- a/client_test.go
+++ b/client_test.go
@@ -78,11 +78,15 @@ func TestCaptureMessageEmptyString(t *testing.T) {
 		},
 	}
 	got := transport.lastEvent
-	opts := cmp.Transformer("SimplifiedEvent", func(e *Event) *Event {
-		return &Event{
-			Exception: e.Exception,
-		}
-	})
+	opts := cmp.Options{
+		cmpopts.IgnoreFields(Event{}, "sdkMetaData"),
+		cmp.Transformer("SimplifiedEvent", func(e *Event) *Event {
+			return &Event{
+				Exception: e.Exception,
+			}
+		}),
+	}
+
 	if diff := cmp.Diff(want, got, opts); diff != "" {
 		t.Errorf("(-want +got):\n%s", diff)
 	}
@@ -282,7 +286,7 @@ func TestCaptureEvent(t *testing.T) {
 		},
 	}
 	got := transport.lastEvent
-	opts := cmp.Options{cmpopts.IgnoreFields(Event{}, "Release")}
+	opts := cmp.Options{cmpopts.IgnoreFields(Event{}, "Release", "sdkMetaData")}
 	if diff := cmp.Diff(want, got, opts); diff != "" {
 		t.Errorf("Event mismatch (-want +got):\n%s", diff)
 	}
@@ -309,11 +313,14 @@ func TestCaptureEventNil(t *testing.T) {
 		},
 	}
 	got := transport.lastEvent
-	opts := cmp.Transformer("SimplifiedEvent", func(e *Event) *Event {
-		return &Event{
-			Exception: e.Exception,
-		}
-	})
+	opts := cmp.Options{
+		cmpopts.IgnoreFields(Event{}, "sdkMetaData"),
+		cmp.Transformer("SimplifiedEvent", func(e *Event) *Event {
+			return &Event{
+				Exception: e.Exception,
+			}
+		}),
+	}
 	if diff := cmp.Diff(want, got, opts); diff != "" {
 		t.Errorf("(-want +got):\n%s", diff)
 	}
@@ -476,13 +483,17 @@ func TestRecover(t *testing.T) {
 			t.Fatalf("events = %s\ngot %d events, want 1", b, len(events))
 		}
 		got := events[0]
-		opts := cmp.Transformer("SimplifiedEvent", func(e *Event) *Event {
-			return &Event{
-				Message:   e.Message,
-				Exception: e.Exception,
-				Level:     e.Level,
-			}
-		})
+		opts := cmp.Options{
+			cmpopts.IgnoreFields(Event{}, "sdkMetaData"),
+			cmp.Transformer("SimplifiedEvent", func(e *Event) *Event {
+				return &Event{
+					Message:   e.Message,
+					Exception: e.Exception,
+					Level:     e.Level,
+				}
+			}),
+		}
+
 		if diff := cmp.Diff(want, got, opts); diff != "" {
 			t.Errorf("(-want +got):\n%s", diff)
 		}
diff --git a/fasthttp/sentryfasthttp_test.go b/fasthttp/sentryfasthttp_test.go
index 0c718636..3ee8b666 100644
--- a/fasthttp/sentryfasthttp_test.go
+++ b/fasthttp/sentryfasthttp_test.go
@@ -208,6 +208,7 @@ func TestIntegration(t *testing.T) {
 			sentry.Event{},
 			"Contexts", "EventID", "Extra", "Platform", "Modules",
 			"Release", "Sdk", "ServerName", "Tags", "Timestamp",
+			"sdkMetaData",
 		),
 		cmpopts.IgnoreMapEntries(func(k string, v string) bool {
 			// fasthttp changed Content-Length behavior in
diff --git a/http/sentryhttp_test.go b/http/sentryhttp_test.go
index 9b8efb54..2d97ce8b 100644
--- a/http/sentryhttp_test.go
+++ b/http/sentryhttp_test.go
@@ -216,6 +216,7 @@ func TestIntegration(t *testing.T) {
 			sentry.Event{},
 			"Contexts", "EventID", "Extra", "Platform", "Modules",
 			"Release", "Sdk", "ServerName", "Tags", "Timestamp",
+			"sdkMetaData",
 		),
 		cmpopts.IgnoreFields(
 			sentry.Request{},
diff --git a/interfaces.go b/interfaces.go
index 9658e702..341f8aa7 100644
--- a/interfaces.go
+++ b/interfaces.go
@@ -221,7 +221,7 @@ const (
 	DynamicSamplingContextKey SDKMetaDataKey = "DynamicSamplingContext"
 )
 
-// SDKMetaData is a struct to stash data which is needed at some point in the SDK's event processing pipeline
+// sdkMetaData is a struct to stash data which is needed at some point in the SDK's event processing pipeline
 // but which shouldn't get send to Sentry.
 type SDKMetaData struct {
 	DynamicSamplingContextKey DynamicSamplingContext
@@ -266,7 +266,7 @@ type Event struct {
 
 	// The fields below are not part of the final JSON payload.
 
-	SDKMetaData SDKMetaData `json:"-"`
+	sdkMetaData SDKMetaData
 }
 
 // TODO: Event.Contexts map[string]interface{} => map[string]EventContext,
diff --git a/tracing.go b/tracing.go
index b5a4e199..f8231660 100644
--- a/tracing.go
+++ b/tracing.go
@@ -359,7 +359,7 @@ func (s *Span) toEvent() *Event {
 		Timestamp: s.EndTime,
 		StartTime: s.StartTime,
 		Spans:     finished,
-		SDKMetaData: SDKMetaData{
+		sdkMetaData: SDKMetaData{
 			DynamicSamplingContextKey: s.dynamicSamplingContext,
 		},
 	}
diff --git a/tracing_test.go b/tracing_test.go
index 347a6dde..e012b763 100644
--- a/tracing_test.go
+++ b/tracing_test.go
@@ -152,6 +152,7 @@ func TestStartSpan(t *testing.T) {
 		cmpopts.IgnoreFields(Event{},
 			"Contexts", "EventID", "Level", "Platform",
 			"Release", "Sdk", "ServerName", "Modules",
+			"sdkMetaData",
 		),
 		cmpopts.EquateEmpty(),
 	}
@@ -211,6 +212,7 @@ func TestStartChild(t *testing.T) {
 		cmpopts.IgnoreFields(Event{},
 			"EventID", "Level", "Platform", "Modules",
 			"Release", "Sdk", "ServerName", "Timestamp", "StartTime",
+			"sdkMetaData",
 		),
 		cmpopts.IgnoreMapEntries(func(k string, v interface{}) bool {
 			return k != "trace"
@@ -285,6 +287,7 @@ func TestStartTransaction(t *testing.T) {
 		cmpopts.IgnoreFields(Event{},
 			"Contexts", "EventID", "Level", "Platform",
 			"Release", "Sdk", "ServerName", "Modules",
+			"sdkMetaData",
 		),
 		cmpopts.EquateEmpty(),
 	}
diff --git a/transport.go b/transport.go
index f9168d1c..05bcd3c7 100644
--- a/transport.go
+++ b/transport.go
@@ -98,7 +98,7 @@ func transactionEnvelopeFromBody(event *Event, dsn *Dsn, sentAt time.Time, body
 	var b bytes.Buffer
 	enc := json.NewEncoder(&b)
 
-	dsc := event.SDKMetaData.DynamicSamplingContextKey
+	dsc := event.sdkMetaData.DynamicSamplingContextKey
 	var trace = map[string]string{}
 
 	for k, v := range dsc.Entries {