diff --git a/change_events.go b/change_events.go
index c1f9308f..08a63f82 100644
--- a/change_events.go
+++ b/change_events.go
@@ -19,10 +19,10 @@ type ChangeEvent struct {
 // Payload ChangeEvent Payload
 // https://developer.pagerduty.com/docs/events-api-v2/send-change-events/#example-request-payload
 type Payload struct {
-	Source        string      `json:"source"`
-	Summary       string      `json:"summary"`
-	Timestamp     string      `json:"timestamp"`
-	CustomDetails interface{} `json:"custom_details"`
+	Source        string                 `json:"source"`
+	Summary       string                 `json:"summary"`
+	Timestamp     string                 `json:"timestamp"`
+	CustomDetails map[string]interface{} `json:"custom_details"`
 }
 
 // Link represents a single link in a ChangeEvent
diff --git a/change_events_test.go b/change_events_test.go
index 3abf84e8..46b3e490 100644
--- a/change_events_test.go
+++ b/change_events_test.go
@@ -38,7 +38,7 @@ func TestChangeEvent_Create(t *testing.T) {
 		Message: "Change event processed",
 	}
 
-	eventDetails := map[string]string{"DetailKey1": "DetailValue1", "DetailKey2": "DetailValue2"}
+	eventDetails := map[string]interface{}{"DetailKey1": "DetailValue1", "DetailKey2": "DetailValue2"}
 	ce := ChangeEvent{
 		RoutingKey: "a0000000aa0000a0a000aa0a0a0aa000",
 		Payload: Payload{
@@ -89,7 +89,7 @@ func TestChangeEvent_CreateWithPayloadVerification(t *testing.T) {
 		HTTPClient:          defaultHTTPClient,
 	}
 
-	eventDetails := map[string]string{"DetailKey1": "DetailValue1", "DetailKey2": "DetailValue2"}
+	eventDetails := map[string]interface{}{"DetailKey1": "DetailValue1", "DetailKey2": "DetailValue2"}
 	ce := ChangeEvent{
 		RoutingKey: "a0000000aa0000a0a000aa0a0a0aa000",
 		Payload: Payload{