diff --git a/pkg/apis/eventing/v1alpha1/trigger_conversion.go b/pkg/apis/eventing/v1alpha1/trigger_conversion.go
index fb9c0631809..eac948d8ec8 100644
--- a/pkg/apis/eventing/v1alpha1/trigger_conversion.go
+++ b/pkg/apis/eventing/v1alpha1/trigger_conversion.go
@@ -34,14 +34,19 @@ func (source *Trigger) ConvertTo(ctx context.Context, obj apis.Convertible) erro
 		sink.Spec.Subscriber = source.Spec.Subscriber
 		if source.Spec.Filter != nil {
 			sink.Spec.Filter = &v1beta1.TriggerFilter{
-				Attributes: make(v1beta1.TriggerFilterAttributes, 0),
 			}
 			if source.Spec.Filter.Attributes != nil {
+				sink.Spec.Filter = &v1beta1.TriggerFilter{
+					Attributes: make(v1beta1.TriggerFilterAttributes, 0),
+				}
 				for k, v := range *source.Spec.Filter.Attributes {
 					sink.Spec.Filter.Attributes[k] = v
 				}
 			}
 			if source.Spec.Filter.DeprecatedSourceAndType != nil {
+				sink.Spec.Filter = &v1beta1.TriggerFilter{
+					Attributes: make(v1beta1.TriggerFilterAttributes, 0),
+				}
 				sink.Spec.Filter.Attributes["source"] = source.Spec.Filter.DeprecatedSourceAndType.Source
 				sink.Spec.Filter.Attributes["type"] = source.Spec.Filter.DeprecatedSourceAndType.Type
 			}
@@ -63,7 +68,7 @@ func (sink *Trigger) ConvertFrom(ctx context.Context, obj apis.Convertible) erro
 		sink.ObjectMeta = source.ObjectMeta
 		sink.Spec.Broker = source.Spec.Broker
 		sink.Spec.Subscriber = source.Spec.Subscriber
-		if source.Spec.Filter != nil {
+		if source.Spec.Filter != nil && source.Spec.Filter.Attributes != nil {
 			attributes := TriggerFilterAttributes{}
 			for k, v := range source.Spec.Filter.Attributes {
 				attributes[k] = v