diff --git a/modules/@angular/compiler/src/i18n/digest.ts b/modules/@angular/compiler/src/i18n/digest.ts
index d00bf80354..6bc2ff0dd4 100644
--- a/modules/@angular/compiler/src/i18n/digest.ts
+++ b/modules/@angular/compiler/src/i18n/digest.ts
@@ -9,13 +9,13 @@
 import * as i18n from './i18n_ast';
 
 export function digest(message: i18n.Message): string {
-  return sha1(serializeNodes(message.nodes).join('') + `[${message.meaning}]`);
+  return message.id || sha1(serializeNodes(message.nodes).join('') + `[${message.meaning}]`);
 }
 
 export function decimalDigest(message: i18n.Message): string {
   const visitor = new _SerializerIgnoreIcuExpVisitor();
   const parts = message.nodes.map(a => a.visit(visitor, null));
-  return computeMsgId(parts.join(''), message.meaning);
+  return message.id || computeMsgId(parts.join(''), message.meaning);
 }
 
 /**