diff --git a/util/protogen/internalgengo/file.go b/util/protogen/internalgengo/file.go
index b5b351c..cd54fa0 100644
--- a/util/protogen/internalgengo/file.go
+++ b/util/protogen/internalgengo/file.go
@@ -148,7 +148,7 @@ func emitOneofGettersSetters(g *protogen.GeneratedFile, msg *protogen.Message, f
 		g.P("}")
 
 		ft := fieldType(g, ff)
-		emitGetterSetter(g, ff.GoIdent.GoName, ff.GoName, ft.String(), "nil")
+		emitGetterSetter(g, ff.GoIdent.GoName, ff.GoName, ft.String(), fieldDefaultValue(ff))
 	}
 }