diff --git a/shared/definition.go b/shared/definition.go
index 0a7c673b..dde3e441 100644
--- a/shared/definition.go
+++ b/shared/definition.go
@@ -41,7 +41,7 @@ const (
 )
 
 // UnmarshalYAML validates the filter type.
-func (d DefinitionFilterType) UnmarshalYAML(unmarshal func(interface{}) error) error {
+func (d *DefinitionFilterType) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	var filterType string
 
 	err := unmarshal(&filterType)
@@ -53,6 +53,8 @@ func (d DefinitionFilterType) UnmarshalYAML(unmarshal func(interface{}) error) e
 		return fmt.Errorf("Invalid filter type %q", filterType)
 	}
 
+	*d = DefinitionFilterType(filterType)
+
 	return nil
 }