diff --git a/pagerduty/resource_pagerduty_service.go b/pagerduty/resource_pagerduty_service.go
index 663e97766..09252da53 100644
--- a/pagerduty/resource_pagerduty_service.go
+++ b/pagerduty/resource_pagerduty_service.go
@@ -504,7 +504,12 @@ func flattenService(d *schema.ResourceData, service *pagerduty.Service) error {
 }
 
 func expandAlertGroupingParameters(v interface{}) *pagerduty.AlertGroupingParameters {
-	riur := v.([]interface{})[0].(map[string]interface{})
+	parameters := v.([]interface{})[0]
+	if parameters == nil {
+		parameters = map[string]interface{}{"type": ""}
+	}
+
+	riur := parameters.(map[string]interface{})
 	alertGroupingParameters := &pagerduty.AlertGroupingParameters{
 		Config: &pagerduty.AlertGroupingConfig{},
 	}