diff --git a/src/pkg/runtime/type.go b/src/pkg/runtime/type.go
index 374754afaf..276dbc0c9c 100644
--- a/src/pkg/runtime/type.go
+++ b/src/pkg/runtime/type.go
@@ -26,6 +26,7 @@ type rtype struct {
 	string     *string
 	*uncommonType
 	ptrToThis *rtype
+	zero      unsafe.Pointer
 }
 
 type _method struct {