diff --git a/lib/i18n.js b/lib/i18n.js
index 130f0c94dfa92b2e2b9da0bb21f0928393fb1c4e..c6600cfeaae9c33778374f7683e26b2c8e7776a0 100644
--- a/lib/i18n.js
+++ b/lib/i18n.js
@@ -263,5 +263,7 @@ var format = exports.format = function (fmt, obj, named) {
     return fmt.replace(/%\(\s*([^)]+)\s*\)/g, function(m, v){
       return String(obj[v]);
     });
+  } else {
+    return fmt;
   }
 };
diff --git a/tests/i18n-tests.js b/tests/i18n-tests.js
index 9001546ba514aca3041a6ccb7f3270b49946f6e2..88287ec5d0ebed4d9fb3ec04b7a8134999a6ccfe 100755
--- a/tests/i18n-tests.js
+++ b/tests/i18n-tests.js
@@ -27,7 +27,7 @@ suite.addBatch({
   "format a string with named values": {
     topic: function () {
       var params = { salutation: "Hello", place: "World" };
-      return i18n.format("%(salutation)s %(place)s!", params, true);
+      return i18n.format("%(salutation) %(place)!", params);
     },
     "was interpolated": function (err, str) {
       assert.equal(str, "Hello World!");